(6.10.7) XIV) SHALL - Involvement of interested parties in review: For their involvement in the critical review, see chapter 6.10 and separate guidance document on "Review schemes for LCA". [ISO!] . 6.11 Identifying critical review needs (Refers to ISO 14044:2006 chapter 4.2.8.3) Introduction A critical review shall be performed by experts that have not been involved in the performance of the LCI/LCA study. This is generally beneficial for the quality and credibility and hence value of the study. This holds true also for exclusively in-house applications, even though in such cases there is no formal requirement for a critical review. Type of review and ILCD compliance The required type of critical review (e.g. independent internal review, independent external review, (external) panel review, etc.), depends on the intended applications of the LCI/LCA study. In the ILCD Handbook this is defined in the separate document “Review schemes for LCA”


In the ILCD Handbook this is defined in the separate document “Review schemes for LCA”. An accordingly performed review meeting the ILCD minimum requirements will automatically include conformity with ISO 14040 and 14044:2006 (and 14025 for Environmental Product Declarations (EPDs)). Note that certain LCA application schemes (such as e.g. Type I Ecolabel schemes) have own review requirements that have to be met as well. The details on the review scope, methods and review documentation can be found in the separate document "Review scope, methods and documentation". The minimum requirements on reviewer qualification are given in the separate document "Reviewer qualification". This qualification covers knowledge and experience in LCA methodology, in the review process, and in the analysed processes / sectors.

European Commission – JRC, ILCD Handbook: General Guide for LCA (2010)


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 6 Scope definition - what to analyse and how Early decision on review It is useful already during the scope definition to decide whether a critical review will be done, and if so which form of review and performed by whom (see chapter 11 and separate guidance document on review in LCA). This early decision will allow the data collection, documentation and reporting of the LCI/LCA study to be tailored to meet the requirements of the review, typically shortening and lowering the overall effort. An early decision also allows running an inter-active concurrent review process. In a concurrent review the reviewers are given the opportunity to comment already on the goal and scope definition prior to the onset of the inventory analysis, and possibly on interim results of the impact assessment and interpretation before the reporting


This way their comments can guide the process of the LCA and can often prevent unpleasant surprises at the end of the project, e.g. additional data needs or even unsuitable comparisons that can set back a comparative assertion by many months. A concurrent review generally also further improves the credibility of the study. For “Meso / macro-level decision support” LCAs (Situation B) the affected stakeholders shall be involved in deciding about the assumption scenarios. This can be done as part of the review; in this case, it is beneficial to start the review process from the onset of the study. For the reference to the scope and methods of the review and its documentation, see chapter 11. Provisions: 6.11 Identifying critical review needs Applicable to Situation A, B, and C, implicitly differentiated. Fully applicable to all types of deliverables, implicitly differentiated


Provisions: 6.11 Identifying critical review needs Applicable to Situation A, B, and C, implicitly differentiated. Fully applicable to all types of deliverables, implicitly differentiated. I) SHALL - Review?: Decide whether a critical review shall be performed and if so: [ISO!] I.a) Review type: Decide along the provisions of the separate document “Review schemes for Life Cycle Assessment (LCA)” which type of review is to be performed as minimum. Note that an accompanying review can be beneficial. For Situation B, it can moreover help to organise the best attainable consensus among interested parties, which is required for certain scope decisions (see provisions of chapter 6.5.4). I.b) Reviewer(s): It is recommended to decide at this point who is/are the reviewer(s). The minimum requirements on reviewer qualification are given in the separate documents "Reviewer qualification"


The minimum requirements on reviewer qualification are given in the separate documents "Reviewer qualification". Notes: An overview of the review requirements and the reference to the review scope methods and documentation requirements are given in chapter 11. 6.12 Planning reporting (Refers to aspects of several ISO 14044:2006 chapters and relates to chapter 5) Introduction Reporting is a vital element of any LCA. Without clear and effective documentation to experts and communication to decision makers, LCAs can be subject to erroneous and misleading use and will not contribute to improving environmental performance. Reporting shall be objective and transparent, and there should be a clear indication of what has and


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 6 Scope definition - what to analyse and how what has not been included in the study and which conclusions and recommendations the outcome a comparative study supports and what now. The form and levels of reporting depends primarily on three factors:  the type of deliverable(s) of the study,  the purpose and intended applications of the study and report, and  the intended target audience (especially technical or non-technical and internal or thirdparty/public). This ensures that the actually required documentation will be collected throughout the project. Next to general purpose reports that will be sketched in this chapter and chapter 10.3, the various applications of LCA may have their own, specific form of reporting (e.g. Environmental Product Declarations (EPDs) or the reporting of indirect effects in Environmental Management reports of sites or companies, etc.)


Environmental Product Declarations (EPDs) or the reporting of indirect effects in Environmental Management reports of sites or companies, etc.). These will not be addressed in this document as they are out of the scope. Please refer to the respective application to identify the specific reporting needs. Forms of reporting Three principally different forms of reporting are relevant that are often used also in combination (more details see chapter 10.3):  a “classical” detailed project report, i.e. an often comprehensive text document typically with graphics and tables and that provides all relevant details e.g. on the analysed system(s) or developed LCIA methods, and the project in which the work was done. It is directed at LCA experts, but should contain an executive summary for non-technical audience


on the analysed system(s) or developed LCIA methods, and the project in which the work was done. It is directed at LCA experts, but should contain an executive summary for non-technical audience. The full report provides detailed documentation about the system (or LCIA methods), their modelling, on assumptions and – especially in case of comparative assertions – on interpretation including conclusions and recommendations, if any. Confidential information can be foreseen to be documented in a separate, complementary report that is not published but only made available to the reviewers under confidentiality. If the detailed report is used for third party information, it shall contain a reference (preferably a hyperlink) where any related review reports can be easily accessed.  a more condensed and formalised, electronically exchangeable report in form of a data set


 a more condensed and formalised, electronically exchangeable report in form of a data set. A data set is suitable for documenting individual unit processes or systems (as Process data set) but not for documenting the outcome of comparisons. It is also suitable for LCIA methods (LCIA method data set). This form is also directed at LCA experts, mainly as data input for use in other LCA studies. As an electronic data set it allows other users importing the inventory and other technical details without manual transfer of values to their LCA software, i.e. limiting errors and directly using the inventory data (or impact factors) for modelling and analysing their own systems.  a very condensed Executive Summary report of e.g. 1 to 2 pages that condenses the detailed project report to its essence in non-technical language. Note that this report is the one that should also be used in the detailed project report


1 to 2 pages that condenses the detailed project report to its essence in non-technical language. Note that this report is the one that should also be used in the detailed project report. If it is used as separate report for third-party information it shall contain a reference (preferably a hyperlink) where the detailed report and any related review reports can be easily accessed. Whenever the final output type of the study is a data set or when data sets are developed and should stay available for subsequent uses, the most useful way of reporting is to combine a well documented Process data set or LCIA method data set (being a condensed


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 6 Scope definition - what to analyse and how version of the detailed report) and the detailed report and any review reports as electronic attachment to that data set. The ILCD Handbook comes along with an electronic template for LCA reports and with the ILCD reference format as an electronic data set format that both should be foreseen to be used (details see chapter 10). Levels of reporting Three levels of reporting should be distinguished:  reports or data sets for internal use,  reports or data sets for external use (i.e. to be made available to a limited, well defined list of recipients with at least one organisation that has not participated in the LCI/LCA study), and  comparative assertion reports that are foreseen to be made available to the (nontechnical) public. The different levels of reporting and the specific requirements for each of them are presented in chapter 10.3


The different levels of reporting and the specific requirements for each of them are presented in chapter 10.3. Provisions: 6.12 Planning reporting Applicable to Situation A, B, and C, implicitly differentiated. Fully applicable to all types of deliverables, differentiated. I) SHALL - Reflecting on the main type of deliverable (i.e. study or data set) and in line with the decision on the target audience(s) and intended application(s) (see chapter 5.2), decide on form and level of reporting: I.a) Form of reporting: Decide which form(s) of reporting shall be used to meet the need of the intended application(s) and target audience(s): [ISO!] I.a.i) detailed report (including non-technical executive summary), I.a.ii) data set, I.a.iii) data set plus detailed report, or I.a.iv) non-technical executive summary (with references to the full report and review reports, if review has been performed)


I.a.v) The electronic ILCD LCA report template and LCI data set format should be foreseen to be used for reporting. Confidential information can be documented in a separate, complementary report that is not published but only made available to the reviewers under confidentiality. Note that any form of reporting, also more condensed ones, shall ensure that the contained information cannot easily and unintentionally be misunderstood or misinterpreted beyond what is supported by the study. I.b) Level of reporting: Decide which level of reporting shall be used in accordance with the defined goal. The main levels are: I.b.i) internal I.b.ii) external (but limited, well defined recipients)


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 6 Scope definition - what to analyse and how I.b.iii) third-party report, publicly accessible I.b.iv) report on comparisons, publicly accessible For the detailed reporting requirements see chapter 10.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results (Refers to ISO 14044:2006 chapter 4.3) 7.1 Introduction and overview (Refers to ISO 14044:2006 chapter 4.3.1 and 4.3.2.3 and other aspects of ISO 14044:2006 chapter 4.3) Introduction During the life cycle inventory phase the actual data collection and modelling of the system (e.g. product) is to be done. This is to be done in line with the goal definition and meeting the requirements derived in the scope phase. The LCI results are the input to the subsequent LCIA phase. The results of the LCI work also provide feedback to the scope phase as initial scope settings often needs adjustments. Typically, the LCI phase requires the highest efforts and resources of an LCA: for data collection, acquisition, and modelling


Typically, the LCI phase requires the highest efforts and resources of an LCA: for data collection, acquisition, and modelling. Note the limitation of the scope of the LCA approach: it relates exclusively to impacts that are potentially caused by interventions between the analysed system and the ecosphere, and caused during normal and abnormal operating conditions of the included processes, but excluding accidents, spills, and the like. See the related information in chapter 6.8.2. If non-LCA effects are analysed, they must be inventoried, aggregated and interpreted separately from the life cycle inventory. This document is not explicitly providing guidance on these. While it may help to ensure taking a consistent approach, dedicated guidance and tools should be consulted or used. Overview The first steps of the LCI work further detail and concretize the requirements derived in the scope phase, e.g. on specific data sources to be used, planning data collection, etc


Overview The first steps of the LCI work further detail and concretize the requirements derived in the scope phase, e.g. on specific data sources to be used, planning data collection, etc. The requirements themselves are however always to be understood to be a scope issue. The inventory phase involves the collection of the required data for ...  Flows to and from processes: - Elementary flows110 (such as resources and emissions but also other interventions with the ecosphere such as land use), - Product flows (i.e. goods and services both as "product" of a process and as input/consumables) that link the analysed process with other processes, and - Waste flows (both wastewater and solid/liquid wastes) that need to be linked with waste management processes to ensure a complete modelling of the related efforts and environmental impacts.  Other information identified in the scope definition as relevant for the analysed system. This includes statistical data (e.g


 Other information identified in the scope definition as relevant for the analysed system. This includes statistical data (e.g. market mix data), process and product characteristics 110 The ILCD reference elementary flows should be used wherever possible and relevant, ensuring compatible inventories and avoiding multiple occurrences of the same flows in joint/aggregated inventories, when combining data sets from different sources.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results (e.g. functions and functional units), and all other data and information, except for those directly related to impact assessment. The specific kind of life cycle inventory work depends on the deliverable of the study; not all of the following steps are required for all of these. In its entirety, life cycle inventory work means:  Identifying the processes that are required for the system (7.2.3 for attributional and 7.2.4 for consequential modelling),  Planning of the collection of the raw data and information, and of data sets from secondary sources (7.3)  Collecting (typically) for the foreground system unit process inventory data for these processes (7.4)


An important aspect is the interim quality control and how to deal with missing inventory data (7.4.2.11)  Developing generic LCI data, especially where average or specific data are not available and cannot be developed, typically due to restrictions in data access or budget (7.5)  Obtaining complementary background data as unit process or LCI result data sets from data providers (7.6),  Averaging LCI data across process or products, including for developing production, supply and consumption mixes (7.7)  Modelling the system by connecting and scaling the data sets correctly, so that the system is providing its functional unit (7.8).  This modelling includes solving multifunctionality of processes in the system. For this step see 7.9 for attributional modelling and – given the different modelling logic - chapter 7.2.4.6 for consequential modelling where this is integral part of the identification of included processes.  Calculating LCI results, i.e


 Calculating LCI results, i.e. summing up all inputs and outputs of all processes within the system boundaries. If entirely modelled, only the reference flow (“final product”) and elementary flows remain in the inventory (7.10). These steps are done in an iterative procedure, as explained in chapter 4 and illustrated in Figure 4 and Figure 5. 7.2 Identifying processes within the system boundaries (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2 and 4.3.2.1) 7.2.1 Introduction and overview (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2 and 4.3.2.1) If the LCI/LCA study goes beyond the analysis and modelling of a single unit process and is to deliver e.g. an LCI results data set or a product comparison report, the whole system is to be analysed: For all life cycle stages included in the system boundaries those processes are identified that must be covered by the later data collection


The way how processes are identified within the system boundaries differs considerably between attributional and consequential modelling. Different processes and data are accordingly required based on the modelling approach; chapters 7.2.3 and 7.2.4 provide the detailed procedures to identify them.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results It is reiterated here what was already stressed in the scope chapter on system boundary setting and what applies to both attributional and consequential modelling: Types of activities that are generally to be included in LCA are all activities under normal and abnormal operating conditions that are related to the analysed system, while not accidents, spills and the like. The system boundary of LCA includes hence for example mining, processing, manufacturing, use, repair and maintenance processes as well as transport, waste treatment and other purchased services such as e.g. cleaning and legal services, marketing, production and decommissioning of capital goods, operation of premises such as retail, storage, administration offices, staff commuting, business travel, etc


cleaning and legal services, marketing, production and decommissioning of capital goods, operation of premises such as retail, storage, administration offices, staff commuting, business travel, etc. In short: all nonaccident activities that are carried out in relationship to the analysed system and that can either be attributed (attributional modelling) to it or expected/modelled to be a consequence of a decision in the foreground of the analysed system (consequential modelling) should be included unless they are quantitatively not relevant, applying the cut-off criteria. Any other omissions shall be documented and considered in the interpretation. 7.2.2 Part-system and system-system relationships A special topic are part-system relationships and system-system relationships that relate to both attributional and consequential modelling and that effectively need the same modelling solution


The related boxes below explain the concepts: Terms and concepts: Part-system relationships including energy related products A part-system relationship refers to a subsystem that is regular part of another system and contributes to its function(s). It can be challenging to correctly model the life cycle of such relationships (both typically being goods, e.g. a starter battery as part of a car; a watersaving shower head as part of a shower; a window as part of a building, etc.): the technical interaction between the analysed part and the full system and its other parts/components is typically to be explicitly considered in the system boundary definition. This is unless the goal and the scope of the study requires or at least permits to look at the part in isolation. The relationship shall be taken into account if the part would be compared with other parts with somewhat different interaction with the system or if analysing improvement options


The relationship shall be taken into account if the part would be compared with other parts with somewhat different interaction with the system or if analysing improvement options. This applies also for attributional modelling, as the part alone cannot perform its ultimate function in isolation, e.g. in time series monitoring of the part with the different models having a different interaction with their systems. If the part can be modelled in isolation and the data and/or report (e.g. an EPD) will be made available externally, the necessity to include the part-system relationship in further uses of the data (e.g. for comparative studies etc.) should be explicitly documented nevertheless. E.g. will different car starter batteries of a substantial different weight result in e.g. a changed battery mount, wiring, etc. The resulting different total weight of the car will also affect the acceleration properties of the car


a changed battery mount, wiring, etc. The resulting different total weight of the car will also affect the acceleration properties of the car. The car therefore needs to be modelled with an accordingly differently sized engine, to keep the comparability of the functional unit of the two car variants. Figure 17 illustrates this. In the mentioned example of the water-saving shower head, the lower water flow allows to save water and energy while still delivering a comparable functional unit. Hence the amount of water and energy consumed in the use stage is to be considered when comparing the use of different shower heads. Depending on the exact goal of the LCI/LCA study (e.g. use of the water-saver for new homes only, or replacement in existing homes) also the potentially smaller water heater installed needs to be considered. This results in the need for different scenarios and hence different processes to be included in the system boundaries. Such


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results energy related products require a clear definition of the relationship and the reality, measurability / quantifiability of the effect. Also intended interactions between processes can be understood as cases of part-system relationships: e.g. a servicing process that is affecting the serviced good and changes its performance (e.g. low friction motor oil), life time (e.g. maintenance and repair processes in general or e.g. differently aggressive cleaning agents), or that causes specific emissions (e.g. Chromium solving / abrasion by aggressive cleaning agents)


maintenance and repair processes in general or e.g. differently aggressive cleaning agents), or that causes specific emissions (e.g. Chromium solving / abrasion by aggressive cleaning agents). In the earlier example of windows, their performance can only be compared in the context of the whole building, as the building‟s heating (and/or cooling) system, solar gains that depend on the window area and orientation, and other aspects must be included for correctly assessing the windows‟ use stage. As said earlier, LCI data of the window itself can still be developed and made available but their use in decision support must be done from a system's perspective. These examples illustrate again that a good technical understanding of the analysed product/part and related systems is an essential pre-requisite for performing a valid LCA, and in an even higher degree for studies that involve part-system relationships. See also the next box for system-system relationships


See also the next box for system-system relationships. Figure 17 Part-system relationships: example of car starter battery for a comparative study or time-series monitoring that cannot be analysed in isolation, as different battery variants (grey) require different e.g. mounts and other parts (blue) and result in different fuel use during the use stage. If they are substantially different in weight this results even in different engine sizes to not change the car (=system) performance, what needs to be considered as well. An apparently similar case to part-system relationships are system-system relationships; the below box explains them and the implications for identifying processes and modelling the system. Terms and concepts: System-system relationships System-system relationships refer to the use of the "analysed system" (e.g. product) in context of one or more, other, generally independent systems (called hereafter "context system"). I.e


product) in context of one or more, other, generally independent systems (called hereafter "context system"). I.e. the analysed system is not regular part of the context system and does not contribute to its function(s) but has primarily other, distinct functions. However, the analysed system is affecting the context system via a co-function, generated waste (e.g. waste heat), or specific emissions111. It may thereby modify the context systems performance and functions. System-system relationships can hence methodologically be a special case of multifunctionality of processes or products. In other cases, the context system "treats" the 111 As these "emissions" are emitted inside the technosphere, i.e. the context system, they are formally no emissions but equivalent to untreated emissions such as raw gas or raw wastewater. For simplicity they are nevertheless called emissions here, looking at them from the perspective of the analysed system. + − + −


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results emission before it leaves the technosphere. The use of e.g. computer or a coffee machine as analysed system in an office building as context system are examples, with heat as a coproduct (during the cold season) and a waste (in the warm season). Note that both systems can be usefully operated also fully independently, other than in part-system relationships. The analysed system and the context system can interact in two different ways that require different modelling: In one case, one or more secondary functions of the analysed system cause changes in the operation of the context system (e.g. for the above examples the heat generated by the analysed computer results in less need for heating of the building and/or more need for cooling - i.e. treating the waste heat - depending on season and country)


treating the waste heat - depending on season and country). This case is methodologically very similar to the specific short-term marginal consequence known in consequential modelling (see chapter 7.2.4.4) and modelled accordingly; this will be detailed in the respective chapter. The main difference is that the consequence here acts directly and not via a market mechanism. In attributional modelling, the co-function (e.g. heat during the cold season) needs to be allocated, applying the 2-step allocation procedure of chapter 7.9.3. For the warm season, when the co-generated heat is in fact a waste heat and cannot be considered a valuable coproduct that would call for an allocation, the de-facto operated waste heat treatment process "air conditioner" is to be modelled within the system boundary112. In another case, the same secondary functions may in addition to changing the operation of the context system also alter it, e.g


In another case, the same secondary functions may in addition to changing the operation of the context system also alter it, e.g. the installed machines or other goods used to operate in the context system. This is the case if the operation of the analysed system is considered in the planning of the context system: E.g. the installed capacity of the building's heating and/or cooling equipment may be different in the above example, if the heat production of the computer is considered when planning the office building. For attributional modelling this case is of relevance if future data is modelled attributionally (e.g. for extrapolating accounting data for future years) and the context system is modelled either considering the effect of the analysed system or not. Note that this is however not a methodological issue of modelling consequences, but of forecasting system planning


Note that this is however not a methodological issue of modelling consequences, but of forecasting system planning. For consequential modelling this is methodologically equivalent to the specific long-term marginal, except that the change in installed capacity is not caused due to the size of the effect in the market, but due to the specific and close micro-level system-system relationship when planning the context system. It is applicable if the secondary consequences are explicitly considered in the planning of the context system. Which of the two cases applies depends on the question whether the secondary functions, waste and emissions have been considered when designing the context system. System-system relationships hence play a role in solving multifunctionality of processes and products and are addressed again in the respective chapters, providing the specific provisions. 112 Note that this is not system expansion.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Figure 18 System-system relationships: example of an electricity using product (e.g. computer, coffee machine, fridge, etc.) as analysed system that is operated within a context system (here: a private home). Due to its secondary product "heat" it is lowering the need for heating in the cold season / high latitudes. At the same time is this "waste heat" increasing the demand for air conditioning in the warm season / tropical climates. Provisions that relate to part-system and system-system relationships are addressed in several chapters that provide LCI modelling provisions, drawing on the concepts detailed here


Provisions that relate to part-system and system-system relationships are addressed in several chapters that provide LCI modelling provisions, drawing on the concepts detailed here. 7.2.3 Identifying processes in attributional modelling (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2 and 4.3.2.1) 7.2.3.1 Introduction and overview (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2 and 4.3.2.1) Attributional modelling depicts the system as it can be observed/measured, linking the single processes within the technosphere along the flow of matter, energy, and services (i.e. the existing113 supply-chain) (see Figure 19 and see again the box in chapter 6.5.2). Figure 19 Schematic and simplified supply-chain life cycle model of a product. The system model is depicting the actual supply chain of production, the product use, and the waste management chain


Figure 19 Schematic and simplified supply-chain life cycle model of a product. The system model is depicting the actual supply chain of production, the product use, and the waste management chain. Not shown in the graphic are the waste management processes for production waste, recycling, as well as transport and other e.g. service processes that are included identically as in the real supply-chain. 113 In the case of extrapolation or scenario modelling this can also be the future supply-chain. heating system air-conditioner electricity using product ... ... ... Use Manufacturer Waste service provider A Waste service provider Aa Waste service provider Ab Tier-2 supplier Aa Tier-1 supplier A Tier-2 supplier Ac Tier-1 supplier B Tier-2 supplier Ab


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results This step of “attribution” is crucial, but only implicitly addressed in ISO. Different approaches have accordingly developed in practice, resulting in inconsistent system boundaries, models, and final results. The following subchapters provide a stepwise guidance for identifying the processes that are to be attributed to the analysed system under attributional modelling. The questions whether to rather collect specific data or to obtain average or generic data sets and whether to work with unit process data or with LCI results are addressed in chapter 7.3


The questions whether to rather collect specific data or to obtain average or generic data sets and whether to work with unit process data or with LCI results are addressed in chapter 7.3. 7.2.3.2 Processes to be attributed to the analysed system (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2 and 4.3.2.1) Introduction and overview The following text guides to a reproducible identification of processes that are to be included in the system boundaries. As a starting point it is good to remember that attributional modelling aims at depicting the reality of the analysed system's processes and life cycle stages (as far as required for the analysed system) in analogy to the supply-chain, use stage, and end-of-life: accordingly, any process that physically handles the analysed product (system) and the goods and services that are physically used to produce it or that causes costs for the production, use, or waste treatment is likely part of the system boundaries


For the production of goods and provision of services as well the waste and end-of-life treatment, the identification of to-be-attributed processes is therefore rather straightforward. For the use stage by final consumers additional criteria have to be used. In practice however this straightforwardness seems not always to result in an appropriate identification of the required processes. Guidance is hence required. Conceptually this guidance starts from the system's functional unit or reference flow (i.e. starting from the central process of the foreground system) to systematically check for to-beincluded processes in the entire foreground system. It then follows a descriptive "supplychain - use - end-of-life" logic to identify all those product and waste flows (or their functional units) that cross the border to or from the background system. All processes that this way can be attributed and quantitatively related to that process are to be identified and quantified


All processes that this way can be attributed and quantitatively related to that process are to be identified and quantified. The technical process flow diagrams for the processes of the foreground system that were initially available or have been developed or expanded during the following procedure help during the inventory data collection, interim quality control, and - if foreseen - third-party review. During the work it is recommended to document the identified processes of the foreground system and the links to the background system in a flow-chart type diagram for each analysed system. This flow chart might be developed starting from the initial one made when defining the system boundary and can serve as starting point for the sub-sequent planning of the data collection. The final version of that flow-chart may also be added to the documentation in the final data set or report


The final version of that flow-chart may also be added to the documentation in the final data set or report. Note also that in practice there is no need to identify the further next indirect levels for an analysed process if  the identified and to be included process is part of the background system, and  a sufficiently good quality LCI data set for this process and its further (upstream or downstream) life cycle is available from former studies or can be obtained from thirdparty data providers.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Identifying the processes Looking at the identification in a more functional/technical perspective, the following levels of processes should in principle114 be attributed to the analysed process or system, starting from the system's functional unit or reference flow, i.e. its central process at level 0. Note that the steps below are no strict and exact, complete requirement, but help in structuring the process of identifying the to-be-included processes for which data is required (see also Figure 20): Level 0 - central process or analysed system  On level115 0 stands that process of the foreground system that directly provides the analysed functional unit(s) or reference flow(s) as its function: E.g


an “injection moulding machine116” that produces a plastic part as a good, a “truck” that is used to provide a transport service as its function, a “field” that grows wheat and straw as goods, a “light bulb” that is used to provide light as a service, a “waste incineration oven” that treats waste as a service, a "vacuum cleaner" that is used to provide a carpet cleaning service in private homes, etc. Note that some of these processes are goods, while others are services or product-service systems. Some processes may physically be perceived as persons117 (e.g. a “painter”118 that paints a façade). Also the use-phase of products is covered by this level. Note that the same applies when working with generic processes that combine properties of one or more processes. The same applies analogously in case wider systems are analysed (e.g


Note that the same applies when working with generic processes that combine properties of one or more processes. The same applies analogously in case wider systems are analysed (e.g. an event, the individual mobility of the citizen of a whole country, or the total governmental consumption within a country as accounting indicators): The difference is that more than one level 0 process is to be identified that together provide the system's functional unit. Level 1 – physical embodiment in the good119  On level 1 stand those goods that (partly or fully) physically end up in the analysed good or other goods that are part of the system: Expanding on the initial examples, these are e.g. the “LPPE polymer” that enters the injection moulding machine that produces the before-mentioned plastic part, or the “N-P-K fertiliser” that partly end ups in the wheat plants cropped on the field


the “LPPE polymer” that enters the injection moulding machine that produces the before-mentioned plastic part, or the “N-P-K fertiliser” that partly end ups in the wheat plants cropped on the field. Other examples: specific "stainless steel parts" that are assembled to form a complex product, “benzene” and “chlorine” that enter a 114 Note that in practice, the relevance of the various processes for the overall environmental impact of the analysed system differs widely. Typically only a quite limited number of processes and flows actually contribute to a relevant degree to the overall impact. The application of cut-off rules along with expert judgement helps in effectively and efficiently identifying the actually relevant processes to be attributed. 115 Note that these levels are used as simple, pragmatic guidance and that the exact definition of the levels can be done somewhat differently, depending on the level of the process (i.e. black box or single operation) one looks at


black box or single operation) one looks at. This does not affect the applicability of the guidance as the levels only serve for rough orientation. 116 Note that e.g. a "machine" is no process, but the process is the operation of the machine. For simplicity and clarity the used equipment or other kind of system that is performing the process is used synonymously for the process of the level. 117 Note that by commonly applied convention the processes that meet the general individual needs of such persons (e.g. food, housing etc.) that e.g. as workers contribute to the production of goods etc. are NOT to be included into the analysed product system. In the cases of physically heavy human work as part of an analysed product system, the additional need for calories should however be included, if relevant according to the cut-off criteria. 118 Strictly the "brush" is the good performing the "painting" process, but this would be rather confusing


118 Strictly the "brush" is the good performing the "painting" process, but this would be rather confusing. 119 This step is not applicable to analysed services.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results reactor that produces various chlorinated benzenes as co-products, the "paint" that is used to paint the façade, etc. Level 2 – contact with the central process or analysed good  On level 2 stand those goods and services that only handle or touch the good or level 0 process by performing a supporting function that supports the provision of the analysed function: E.g


auxiliary materials such as “form oil” to release the injection moulded plastic part, “diesel”, “grease” and other consumables that are needed to operate the truck, “pesticides” that help that the wheat is achieving its yield, “electricity” that operates the lamp but also its “lamp-holder” and “fixings” and the "light bulb packaging", supplementary “fuels” to ensure the necessary waste incineration temperature is reached, “light” and “heat” that are provided in the manufacturing line so the workers can assemble the complex product as well as the “hall” of the line that protects against the weather, "packaging materials" of the vacuum cleaner and the paint, “catalysts” that support the production of the chlorinated benzenes. Other examples: “detergents” and “hot water” used for a floor cleaning process, “solvents” that are used in the paint that is applied in a paint shop, etc


Other examples: “detergents” and “hot water” used for a floor cleaning process, “solvents” that are used in the paint that is applied in a paint shop, etc. These level 2 processes include part-system relationships that need special attention; see the related box in chapter 7.2.2. Level 3 – services for the central process or system  On level 3 we find those processes that do not even touch the analysed process' equipment or analysed good or would provide a direct function for the provision of a service, but that are required to nevertheless run in the background in relationship to the process. Examples are administration, guarding, marketing and legal services, etc. 0) Window 2) Heating / cooling system, ... 1) Window glass, window frame, ... 3) Glass cleaning, ... 0) Window glass 2) ... 1) ... 3) ... ... ... ... ... ... ... ... ... Figure 20 Identifying processes within system boundary, starting from the central process or analysed system


0) Window glass 2) ... 1) ... 3) ... ... ... ... ... ... ... ... ... Figure 20 Identifying processes within system boundary, starting from the central process or analysed system. Example of a window, illustrative: The window is the analysed system and hence set as level 0 (oval to the left). After having identified the processes at the levels 1 to 3, each of them becomes a new level 0 process (here shown: "window glass" as oval in the middle). The related processes on the levels 1 to 3 are identified for each of the new level 0 processes, and so on. Indirect processes beyond level 3  Beyond that level 3 we come to surrounding processes that in fact do not relate directly to the central process or system that we look at but to those processes that were identified in the levels 1 to 3. These indirect processes are identified by now looking at


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results each of the processes that were identified as level 1 to 3 and that are part for the foreground system (or connect the foreground with the background system), applying the same logic of the levels 0 to 3 (see also Figure 20). This is repeated again for the next level processes identified in this way and so on. Note that this does not result in an endless list of processes to be included, as by applying cut-off rules - drawing on experience for similar processes and expert judgement - by far most of these can be excluded. (On applying cut-off rules see chapters 7.4.2.11 and 9.3.2). Examples of such processes that only indirectly via other processes relate to the initially analysed level 0 process are e.g. the “production”, “maintenance”, “repair”, etc


Examples of such processes that only indirectly via other processes relate to the initially analysed level 0 process are e.g. the “production”, “maintenance”, “repair”, etc. of any of the above equipments such as of the injection moulding machine, light bulb, truck, hall, reactor, etc. Other examples are the “tractors” that distribute the named fertilisers and pesticides to the field. Beyond these, we find “R&D” of the equipment and processes, “corporate legal services”, “corporate marketing activities”, “business trips”, “staff commuting”, etc. Frequent errors: General or un-reflected exclusion of activity-types As already addressed in chapter 6.6.2, in LCA practice it can still often be fond that certain types of activities that should be attributed to the analysed system are omitted without sufficient justification. Among these processes, services and investment goods are the most common ones. While it might be justified to e.g


Among these processes, services and investment goods are the most common ones. While it might be justified to e.g. ignore the construction and demolishing of the power plant itself when modelling electricity production (depending of course on the cutoff criteria set), the limited relevance of investment goods certainly does not apply in general. Similarly, are many services in many cases of limited quantitative relevance, but also this can clearly not be generalised. A good example is the wind-power plant, where the plant production and maintenance make up the vast majority of impacts. It is to be checked for the given case along approximations and drawing on former experience, which product and waste flows and which processes can be excluded in line with the cut-off criteria and which not. Chapters 7.4.2.11 and 9.3.2 provide the respective guidance for unit processes, chapter 7.8 for systems


Chapters 7.4.2.11 and 9.3.2 provide the respective guidance for unit processes, chapter 7.8 for systems. This cannot be done on the general level “type of activity”, unless quantitatively justified. 7.2.3.3 Initial description of identified processes (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2) Especially for the processes of the foreground system, an initial description is required. This will be revised when collecting and documenting the unit process data. Details on documentation are given in chapter 10. Unless the deliverable of the LCA is a unit process data set: For those product flows that connect the foreground system with the background system, a detailed specification including of their function and functional unit is required. Provisions: 7.2.3 Identifying processes in attributional modelling Applicable to Situation A and C, as well as the life cycle model(s) of Situation B, except for those process steps that are affected by large-scale consequences


Also applicable to the assumption scenarios under Situation B for which it has been decided to apply attributional modelling. Fully applicable for LCI results, partly terminated systems, LCIA results, and LCA studies (and for unit processes only to complete the system model for completeness check and precision approximation). For black box unit processes as deliverable, only those processes that are foreseen to be included are to be


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Provisions: 7.2.3 Identifying processes in attributional modelling identified, as are the product and waste flows that enter or leave the unit process. For single operation unit processes only the product and waste flows that enter or leave the unit process are to be identified and specified; the named technical flow diagram in that case only consists of one process plus product and waste flows. I) SHALL - Identifying processes within the system boundary: All quantitatively relevant processes shall be identified that are to be attributed to the analysed system(s) and that lay within the system boundary: [ISO+] I.a) Start from central process: This identification should start from the system's functional unit or the reference flow (i.e


from the central process of the foreground system or the analysed system itself). (7.2.3.2) I.b) Foreground system: Stepwise it should be expanded to the entire foreground system. Following a descriptive "supply-chain - use - end-of-life" logic it shall as far as possible identify all relevant product and waste flows (or their functional units) that cross the border to or from the background system. (7.2.3.2) I.c) Background system: The processes in the background system shall be identified in the same "supply-chain - use - end-of-life" logic as applied in the foreground system. A recommended systematic procedure for identification is detailed in the main text of the chapter. (7.2.3.2) Note that it is established practice to embed the foreground system into a third-party or in-house developed general background system of LCI results and/or unit processes


(7.2.3.2) Note that it is established practice to embed the foreground system into a third-party or in-house developed general background system of LCI results and/or unit processes. That means that in practice the identification described above ends with the identification of the product and waste flows that connect the foreground system with the background system. Systems or processes that would be missing in such a general background system are for a given case collected or obtained from third parties as required for the analysed system. I.d) Justify and document exclusions: Any exclusion of relevant individual processes or activity types shall be justified using the cut-off criteria (as defined in chapter 6.6.3). This can build on previous experience including as detailed in related system / product-group specific guidance documents or Product Category Rules (PCRs)


This can build on previous experience including as detailed in related system / product-group specific guidance documents or Product Category Rules (PCRs). The systematic check is described jointly with the same procedure for unit process interim quality control and application of cut-off criteria in chapters 7.4.2.11 and 9.3.2, respectively. In principle all processes are to be inventoried that are to be attributed to the system, as far as they relevantly contribute to the overall environmental impact of the analysed system. This includes in principle - depending on the included life cycle stages and the system boundary in general - activities such as e.g. mining, processing, manufacturing, use, repair and maintenance, transport, waste treatment and other purchased services linked to the analysed system, such as e.g


mining, processing, manufacturing, use, repair and maintenance, transport, waste treatment and other purchased services linked to the analysed system, such as e.g. cleaning and legal services, marketing, production and decommissioning of capital goods, operation of premises such as retail, storage, administration offices, staff commuting and business travel, etc. (7.2.3.2) I.e) Part-system and system-system relationships: Part-system and systemsystem relationships need special attention (e.g. for energy related products) and correct inventorying (concepts see chapter 7.2.2.). (7.2.3.2) I.f) Technical flow diagram, lists of product as and waste from/to background system: It is recommended using the system boundary scheme for overview. Technical flow diagrams of the foreground system and lists of the products and


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Provisions: 7.2.3 Identifying processes in attributional modelling waste that link the foreground with the background system may be used to document the main resource bases, trade-partner countries for consumption mix data and production routes, etc. This can form the basis for the data collection planning and the starting point for later documentation. (7.2.3.1) Note that individual processes within the background system may need to be identified as well - in context of identifying sensitive issues (see 9.2) or if required to meet the specific goal of the study. The requirements regarding technological, geographical and time-related representativeness of the scope chapter 6.8 shall be met


The requirements regarding technological, geographical and time-related representativeness of the scope chapter 6.8 shall be met. (7.2.3.2) Note that the resulting initial list of processes, product and waste flows typically will need a refinement in view of the results of the completed initial life cycle model, impact assessment and interpretation. II) SHALL - Initial processes' description: It is recommended to provide an initial description of the identified unit processes of the foreground system, as well as the details of the functional units of those product and waste flows that link it to the background system. This should be updated in the iterative steps of LCI work and shall reflect in the end the final unit processes of the foreground system


This should be updated in the iterative steps of LCI work and shall reflect in the end the final unit processes of the foreground system. (7.2.3.3) 7.2.4 Identifying processes in consequential modelling (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2, 4.2.3.6.2, and 4.3.2.1) 7.2.4.1 Introduction and overview (Refers to aspects of ISO 14044:2006 chapters 4.2.3.3.2, 4.2.3.6.2, and 4.3.2.1) Introduction If the modelling approach is consequential, the relevant consequences and the related processes are to be identified as detailed below. This is relevant exclusively for cases of multifunctionality in Situations A, B and C1, for processes that are affected by "big" changes (large-scale consequences) in Situation B, and for the "assumption scenarios" in Situation B, in case these include consequential modelling


While this chapter describes the consequential approach in detail, note that some key simplifications are made in the provisions for Situations A, B, and C1 that render the work substantially simpler without relevantly changing the robustness of the results (see chapter 6.5.4). Exclusively for processes that are affected by "big" changes (large-scale consequences) in Situation B and in the assumption scenarios of Situation B this chapter is required to be applied in its detail. The “consequential” LCI modelling framework aims at identifying the consequences of a decision in the foreground system on other processes and systems of the economy and builds the to-be-analysed system around these consequences. One important aspect of consequential modelling is that it is not depicting the actual processes of e.g. the suppliers of a specific product supply-chain as an attributional model does, but it is modelling the forecasted consequences of decisions


the suppliers of a specific product supply-chain as an attributional model does, but it is modelling the forecasted consequences of decisions. These consequences are those processes that are assumed to be operated as reaction to the named decision. In unconstrained and fully informed markets they will in general be those processes that most cost-effectively provide the required function (and the processes that a co-function would supersede). However, unconstrained and fully informed markets are a theoretical, ideal case. In practice other aspects need to be considered.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Primary and secondary consequences, constraints A wide range of mechanisms is discussed among LCA practitioners, how a decision in the foreground system affects other processes and products and what are the primary and secondary consequences (the concept of secondary consequences is explained in chapter 7.2.4.2). These mechanisms range from causing the need to build new production plants in consequence of additionally required materials, parts etc., to market displacement of competing products due to marginal market price changes, consumer behaviour changes, and the like. However, next to far reaching consequences, often secondary consequences and constraints counteract and partly or fully compensate the primary consequences or change them to other consequences. Among these are e.g


Among these are e.g. the economy‟s elasticity, the counteracting changes in the demand for the analysed product, reduced consumption of additional required products in other systems due to market-price changes, and many other secondary consequences (e.g. so called “rebound effects”) as well as contractual, political and other constraints. Required expertise To identify the detailed consequences and marginal processes, next to LCA expertise the following expertise is required, while this depends on which of the mechanisms and models are to be considered in the consequential model:  expertise of technology development forecasting (learning curves, experience curves),  scenario development,  market cost and market forecasting,  technology cost modelling,  general-equilibrium modelling, and  partial-equilibrium modelling


Overview The following subchapters explain the steps towards modelling the consequences for the consequential model:  The first step towards identifying the marginal processes that provide the function and the superseded processes is to identify / decide which primary and secondary consequences and constraints are to be integrated in the model. (chapter 7.2.4.2).  Next is the identification of the processes that are operated or displaced due to the identified consequences (chapter 7.2.4.4).  Analysing the considered consequences and taking into account the selected constraints, the processes are identified and the consequential life cycle is modelled stepwise. This starts from the analysed decision in the foreground system. Figure 21 provides a schematic overview of the provisions on identifying processes in consequential modelling; but note the simplified provisions set for Situation A and B in chapters 6.5.4.2 and 6.5.4.3.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Figure 21 Decision tree for consequential modelling120. Terms, concepts, and explanations see text. Formal and detailed provisions see "Provisions". The collection of the individual unit process data is in principle the same as for attributional modelling and addressed jointly in chapter 7.3. The use of average and generic background data is addressed separately in chapter 7.6. 7.2.4.2 Consequences to be considered (No corresponding ISO 14044:2006 chapter but relates to aspects of chapters 4.2.3.3.2, 4.2.3.6.2, and 4.3.2.1) Wherever in practice consequential modelling is to be applied, the relevant consequences to be considered are to be decided upon


Central in a consequential modelling is a quantitative understanding of the market and how direct and indirect changes in supply and demand of the analysed good or service operate through the market to cause real changes in demand and supply of other goods and services. The range of questions that can be put to consequential LCA studies is vast and these can explicitly or implicitly require including a huge variety of consequences. There is no possibility to identify this in a generally applicable, generic way. It is hence to be decided for the given case. 120 Note that the specific provisions for Situation A and B use some simplifications, as detailed in chapters 6.5.4.2 and 6.5.4.3


It is hence to be decided for the given case. 120 Note that the specific provisions for Situation A and B use some simplifications, as detailed in chapters 6.5.4.2 and 6.5.4.3. Extent of additional demand or supply on process in question (primary consequence only)? Characteristics: • Additional demand does not change market direction, AND does not result in additional / reduced capacity affected processes / systems = “short-term marginal” • Additional aspect: in real, non-monopolised markets never only one marginal process / supplier. “small” “big” LCI model of extra supply and demand: • mix of “short-term marginal” processes / systems (as above) of given time and market (e.g


“small” “big” LCI model of extra supply and demand: • mix of “short-term marginal” processes / systems (as above) of given time and market (e.g. 2020, France) • superseded amount to be adjusted considering secondary consequences and constraints Solving multifunctional processes, order of preference: 1) subdivision 2) virtual subdivision 3) substitution of mix of short-term marginal processes / systems*,**, excluding the to-be-substituted co-function 4) substitution of mix of short-term marginal functions 5) 2-step allocation System-system relationships: Specific short-term marginal or long-term marginal processes / systems. Current market direction? Growing, stable or slightly declining Strongly declining “short-term marginal” = least cost-competitive processes / systems “short-term marginal” = most cost-competitive processes / systems Secondary consequences and constraints counteract and change extent back to “small”? no, i.e. “small” yes, i.e


“small” yes, i.e. still “big” Extent of additional demand or supply changes market direction? yes no Secondary consequences and constraints counteract and avoid relevant effect? no yes “short-term marginal” = market consumption mix of processes / systems Characteristics: • Additional demand does not change market direction, BUT does result in additional / reduced capacity affected processes / systems = “long-term marginal” • Additional aspect: in real, non-monopolised markets never only one marginal process / supplier. LCI model of extra supply and demand: • mix of “long-term marginal” processes / systems (as above) of given time and market (e.g


LCI model of extra supply and demand: • mix of “long-term marginal” processes / systems (as above) of given time and market (e.g. 2020, France) • superseded amount to be adjusted considering secondary consequences and constraints Solving multifunctional processes, order of preference: 1) subdivision 2) virtual subdivision 3) substitution of mix of long-term marginal processes / systems*,** 4) substitution of mix of long-term marginal functions 5) 2-step allocation System-system relationships: Specific long-term marginal processes / systems. Current market direction? “long-term marginal” = least cost-competitive processes / systems “long-term marginal” = most cost-competitive processes / systems * Interim steps (e.g. purification, transport, etc.) shall be modelled inside the system boundary until the quality of the to-be-substituted co-function is actually replacing the superseded process(es)


purification, transport, etc.) shall be modelled inside the system boundary until the quality of the to-be-substituted co-function is actually replacing the superseded process(es). In case of closed-loop or open-loop same primary route recycling and the substitution is not equal 1:1 (e.g. due to down-cycling), the actually substituted amount should be credited; if the specific substituted processes are not known, market value correction shall be applied to the superseded processes‟ inventories. ** The provisions apply also when extra supply is partly or fully unused (e.g. deposited) or undergoing low-value uses (e.g. waste incineration with energy-recovery). These processes contribute to the marginal mix. Analogously, if the extra demand uses otherwise partly or fully unused functions, the “avoided waste treatment”, if any, should be credited to the using system


Analogously, if the extra demand uses otherwise partly or fully unused functions, the “avoided waste treatment”, if any, should be credited to the using system. Characteristics: • Additional demand DOES change market direction, AND hence results in additional / reduced capacity affected processes / systems = specific combination of “long-term marginals” (specific combination of the least and the most costcompetitive ones) • Additional aspect: in real, nonmonopolised markets never only one marginal process / supplier. Growing, stable or slightly declining Strongly declining LCI model of extra supply and demand: • to be analysed specifically, drawing on the other provisions for long-term marginals under the different market directions.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Notwithstanding this but providing basic guidance on this question, the following provisions are made: The following primary consequences should be evaluated for inclusion (unless they are in any case already explicitly required or directly derived from the specific goal of the study):  (a) Processes that are operated as direct market consequence of the decision to meet the additional demand of a product (i.e. “consequential modelling of direct consequences; applied for the full system”).  (b) Processes that supersede / complement co-functions of multifunctional processes that are within the system boundary (i.e. “solving multifunctionality by substitution”) The following consequences are secondary consequences but should be evaluated for inclusion121


“solving multifunctionality by substitution”) The following consequences are secondary consequences but should be evaluated for inclusion121. Note that they may counteract the primary consequences and partially or completely compensate them, in that case they are rebound effects.  Increased general demand for a not required co-function if its market-price is reduced due to its additional availability in secondary consequence of an additional demand for the analysed co-function.  Incentive-effect on processes to increase their efficiency as secondary consequence of a higher price for its determining co-function(s) in consequence of the increased demand. E.g. increased recycling rates (by more collection, better separation etc.) in consequences of a higher market price for the secondary good, off-setting partially the primary route substitution. Or e.g. increased productivity of biofuel crops (e.g


Or e.g. increased productivity of biofuel crops (e.g. by putting more fertiliser etc.) in consequence of an increased market price for biofuels, off-setting partially the additional indirect land-use demand that was exemplified above.  Decreased demand for competing functions (e.g. products) of a not required co-function as secondary consequence of the decreased price of this not required co-function due to increased demand for the analysed co-function and the additional availability of its not required co-function.  Consumer behaviour changes (e.g. additional car use in cities in secondary consequence of reduced traffic-jams in consequence of better traffic management or attractive public transport). Consequences that should only be considered if directly subject of the work and correspondingly named in the goal setting, but not for consequential studies in general


Consequences that should only be considered if directly subject of the work and correspondingly named in the goal setting, but not for consequential studies in general. Among others:  Increased general consumption by consumers due to the reduced price of a product (as they save the money and can spend it on other products). Note that this secondary consequence is counteracted by the fact that the workers in the supply-chain of the cheaper product receive less overall salary and will hence consume less. 121 Note that for a number of cases the secondary consequences may not be applicable at all or it is very difficult to interpret / transfer them. This is often caused by constraints to the analysed process / system or its cofunctions. In some cases, the effect can be that strong, that the consequence is not acting via a homogeneous market, but directly (e.g. district heating with the constraint of very limited mobility of the co-product heat)


district heating with the constraint of very limited mobility of the co-product heat). In such cases, it should be considered to model the specific or generic situation instead of a market consequence.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results Changed consumption patterns as secondary consequence of more time availability to consumers as consequence of a consumer product saving the consumer's time (e.g. dishwashing machine vs. manual dishwashing).  accelerated product / technology investments in the analysed process/technology or competing products or technologies (e.g. solar electricity or competing energy technologies). Terms and concepts: Secondary consequences Secondary consequences are also known as “rebound effects”, “back-fire effects”, “offsetting effects”, “ripple effects”: When modelling consequences in the market as result of the decision to produce a good, a range of mechanisms exist that counteract and partly or fully may compensate them, hence the term “rebound effect”


However, such secondary consequences may also increase the effect of the identified consequence or lead to fully different consequences than the direct ones modelled considering only the primary consequences, hence here the use of the broader and more encompassing term "secondary consequences"122. It is important to note that these effects are typically far from linear and when certain thresholds are passed a complete shift of parts of the market can be the effect (e.g. when the production cost of wind-power makes it fully competitive in certain market segments). A list of these mechanisms is found above this box. That list indicates the complexity of identifying and especially quantifying the typically very specific consequences. For some of these there is even a lack of theoretical models to capture the various primary and secondary consequences and their interaction


For some of these there is even a lack of theoretical models to capture the various primary and secondary consequences and their interaction. This is of course no problem that would be inherent to LCA but to all models that aim at forecasting future developments in market and society context.123 122 It is a relevant characteristic that the primary and secondary consequences on the inventory of analysed product system can be both positive and negative, depending on the specific consequence. The question of increasing or declining markets plays furthermore a large role in identifying the superseded marginal process highly uncertain in future scenarios. For the model of the main product system this has the tendency of higher impacts than obtained with attributional modelling in case of rising markets or lower ones for falling markets


For the model of the main product system this has the tendency of higher impacts than obtained with attributional modelling in case of rising markets or lower ones for falling markets. In fact does the respectively superseded processes represent (very roughly) the extremes in terms of best and worst environmental performance in the market of that product. This is unless investment limitations may lead to install an older technology nevertheless in a growing market. For solving multifunctionality the possible influence on the results is bigger, as often other kinds of products are superseded. That means that already the uncertainty of knowing whether a specific market of e.g. a material or part is growing or falling is a very substantial factor that can change the outcome of the analysis. 123 One effect may be illustrated that shows the difficulty to identify the superseded process due to the complexity of interrelating consequences in the market


123 One effect may be illustrated that shows the difficulty to identify the superseded process due to the complexity of interrelating consequences in the market. It also serves to illustrate the greater robustness of using e.g. the market mix in substitution as a simplified requirement: counteracting market price shifts due to additionally available co-products: An extra availability of the co-produced material “X” would in classical consequential modelling supersede/avoid the production of the least cost-competitive material “Y” (or another production route for material “X”: “Xa”). This would be credited by subtracting the inventory of “Y” (or “Xa”). However, the additional availability of “X” results - along the same logic of market consequences - also in a marginal decrease of the market price for “X”. That means that “X” becomes economically more attractive compared to other competing, functionally equivalent materials (e.g. “U” and “Z”) in all types of applications


That means that “X” becomes economically more attractive compared to other competing, functionally equivalent materials (e.g. “U” and “Z”) in all types of applications. In marginal consequence, marginally less of “U” and “Z” would be produced, as “X” would be replacing them to some degree. Hence the market mix production of “U” and “Z” can equally be argued to be superseded by the co-produced “X”, and not only “Y” or “Xa” as considering only the primary consequences.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results 7.2.4.3 Constraints and other market imperfections to be considered Real markets face various constraints and other market imperfections. Real markets are moreover not fully informed, i.e. the operated technologies and products on the market are not only the most cost competitive ones. Similarly as for the mechanisms and consequences, also constraints can be very diverse. There is no possibility to identify the relevant ones on a general level. They are hence to be identified for the given case


There is no possibility to identify the relevant ones on a general level. They are hence to be identified for the given case. Notwithstanding this but providing basic guidance on this question, the following recommendations are made: Constraints that should be considered in consequential modelling are:  Existing long-term supply-contracts or co-operations that cannot easily be changed  Prohibitingly high costs that are a barrier to changes, such as limited mobility of the products (e.g. for basic construction materials over longer distances, for heat)  Existing or expected political measures / legal constraints that stimulate perceived positive developments or counteract perceived negative developments (e.g. take-back fees for packaging materials, land-fill bans and other technology-related constraints, green tax incentives e.g. for solar energy, material bans, etc.)  Non-scalability of supply of products or natural resources that are required for the modelled system. E.g


for solar energy, material bans, etc.)  Non-scalability of supply of products or natural resources that are required for the modelled system. E.g. hydropower, depending on the country/market (see also chapter 6.8.2), or recycled materials which achieve already a recycling rate close to the feasible maximum. Fully used, dependent co-products of joint production, whose production cannot be scaled up, are of this type of constraint.  Monopolies, where there is hence no choice of the supplier or technology Constraints that may additionally be considered in consequential modelling are:  Other constraints in place or expected to be in place that increase, decrease or block a primary or secondary consequence 7.2.4.4 Identifying the processes of the consequential model (No corresponding ISO 14044:2006 chapter but relates to aspects of chapters 4.2.3.3.2, 4.2.3.6.2, and 4.3.2.1) Overview The next step is to identify the specific processes that are to be modelled, i.e


the processes that are operated or displaced as effect of the considered consequences and taking into account the relevant constraints. Apart from using or developing data that sufficiently represents the year for which the scenario is made (e.g. 2020), as a general guidance the following criteria are to be considered for the consequential modelling of the primary consequences "(a)" and "(b)" (see above in chapter 7.2.4.2):  Size of effect (either "small" or "big"),  market situation (i.e. either "growing, stable or slightly declining" OR "strongly declining" market), and  cost-competitiveness of alternative processes (i.e. technologies). The following text provides more details:


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results The first step: consider the primary consequence and the size of the effect The size of the effect of the consequences on other processes in the economy matters in so far, as there are two main cases to be differentiated. In the first step only the primary consequence (a) in the market (see above) is considered; this is the consequence classical consequential modelling has initially only been looking at:  Is the size of the effect "small"?: - The size of the effect is so small that it can be assumed that the analysed decision is NOT able to via market effects directly cause an increase in capacity to meet the additional demand or a reduction of existing capacity in consequence of the additional supply, respectively


This increase or reduction in capacity is understood to be a change in addition to anyway ongoing installation or decommissioning in the market. Note that this applies - as always - not only to production capacity e.g. of materials or energy carriers, but also to the available capacity of services. - The effect should generally be considered small in this sense, if the annual amount of additional demand or supply is smaller than the average percentage of annual replacement of capacity (see chapter 5.3.6) of the annual supply of that function or system in the given market; if that average percentage is over 5 %, 5 % should be used instead. This is for orientation only and can be for a given case changed to be smaller or bigger upon the argumentation that the change in demand or supply is directly triggering changes in demand and not only via a marginal accumulative effect in contribution to the general market demand/signal


Given the elasticity of markets, counteracting secondary consequences and constraints, it can be assumed that small changes in demand and supply do not trigger long-term investments in real markets. The signal they send is too small to overcome the threshold that would have to be overcome to structurally change capacity.  Is the size of the effect "big"?: - The size of the effect is big enough that it can be assumed that the analysed decision IS able to via market effects directly cause an increase in capacity to meet the additional demand or a reduction of existing capacity in consequence of the additional supply, respectively. - This should be generally assumed, if the annual amount of additional demand or supply is bigger than the average percentage of annual replacement of capacity (see chapter 5.3.6) of the annual supply of that function or system in the given market; if that average percentage is over 5 %, 5 % should be used instead


As above, the percentage is for orientation and can be changed upon analogous argumentation as for the "small " effect above. If the size of the effect is "small", the affected processes / systems are always the "shortterm marginal" processes / systems. If it is "big": The second step: consider secondary consequences and constraints Depending on the size of the effect and considering secondary consequences and constraints, the processes mix that best represents the superseded processes is to be narrowed down, as follows:  If the size of the effect - considering only the primary market consequence - is "small", it should first checked whether secondary consequences and constraints in the market counteract the primary consequence (rebound), so that the net effect is "close to zero" (i.e. different from "small" in the previously described sense), compared to the full effect


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results after the primary consequence. Is that the case, the "short-term marginal" is best represented by the "average market consumption mix" of the processes / systems (i.e. the same as the average background data in attributional modelling).  If the size of the effect - considering only the primary market consequence - is "big", it should next be checked whether secondary consequences and market constraints counteract the effect, so it is not "big" anymore, but "small". In that case the above provisions for "small" effects apply for this process.  If secondary consequences and market constraints do not counteract the primary consequences effect strong enough to change it be "small" it must still be considered "big"


 If secondary consequences and market constraints do not counteract the primary consequences effect strong enough to change it be "small" it must still be considered "big". However, the quantitative extent and the affected processes might have been changed by the secondary consequences and constraints. This has to be analysed specifically, as to correctly identify the final consequences. The next steps: market situation and the cost-competitiveness The processes / systems that will be affected depend on the specific market situation and the cost-competitiveness of the alternative processes that can provide the required function. Two cases are to be differentiated regarding the market situation:  a mid-term growing, stable or only slightly declining market, i.e. declining not more than the average displacement rate of capital equipment,  a mid-term strongly declining market, i.e. declining more than the average displacement rate of capital equipment for the respective equipment


declining more than the average displacement rate of capital equipment for the respective equipment. The above named average displacement rate in % is obtained by dividing 100 years by the average or typical life time of the capital equipment. E.g. a plant for producing a material X might have a life time of 25 years. Accordingly, 100 years / 25 years = 4 % are replaced annually. Regarding the "market" it is to be stressed that here the market of the specific e.g. commodity or product should be used and not their broader functions or product groups but also not the market of the specific brand: the market for a specific commodity (e.g. cadmium) or product (e.g. lead based solder paste) might be declining, while the market of some of the functions of the commodity (e.g. energy-storage in batteries, solar energy capturing in thin film solar panels) or the product group to which the product belongs (e.g. solder paste in general) might be growing, and vice versa


energy-storage in batteries, solar energy capturing in thin film solar panels) or the product group to which the product belongs (e.g. solder paste in general) might be growing, and vice versa. As especially constraints may often act directly or indirectly on specific commodities or products (while seldom on the level of brands), their specific market is of relevance here. Based on the above definitions and two cases, the next question for the situation of "big" effects is whether the extent of additional demand or supply is changing the direction of the market, i.e. from a "strongly declining" market to a "slightly declining, stable, or growing" market OR vice versa. If this is NOT the case, the affected processes / systems are always the "long-term marginal" processes / systems


If this is NOT the case, the affected processes / systems are always the "long-term marginal" processes / systems. The next question - for both "small" and "big" effects (while not changing the market direction) is the question of the current market direction and how it modifies which processes are affected by additional demand or supply: In a growing (or at least not strongly declining) market, an additional demand for more capacity for a function can be reasonably assumed to be met by installing the most cost-competitive e.g. technology, using the most costcompetitive raw material route, operating the most cost-competitive waste treatment service, etc. Similarly, for additional short-term demand, the most cost-competitive processes will be used. If a market is however strongly declining, additional demand for more capacity will not be met by installing new capacity, but by NOT decommissioning existing capacity (that


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results otherwise would have been decommissioned, i.e. keeping the least cost-competitive ones in operation). Again, in analogy, also for additional short-term demand, the least costcompetitive supplies will be used. Accordingly, if the market is "growing, stable, or slightly declining", the "short-term marginal" (for "small" effects) and the "long-term marginal" (for "big" effects) are the most cost competitive processes / systems. If the market is "strongly declining" these are the "least cost-competitive" processes / systems, for both "small" and "big" effects


If the market is "strongly declining" these are the "least cost-competitive" processes / systems, for both "small" and "big" effects. If however the extent of additional demand or supply is "big" and IS also changing the direction of the market, a part of the affected processes / systems are those that are affected in strongly falling markets and another part those of growing, stable or slightly declining markets, i.e. a specific combination of two different sets of "long-term" marginals, depending on the share of capacity affected. The final step: identifying the mix of "short-term" or "long-term" marginal processes / systems There is the general lack of full information in the market and a high uncertainty in determining future cost competitiveness of processes and systems


This has the effect - as reality shows - that in most markets several alternative, similarly cost-efficient alternatives compete and are installed at the same time; there is no strict “the one, most cost-efficient technology only” logic in the real world124. An example may be the production of steel in China in 2015, where the (one or several) marginal processes are those steel plants and ore/scrap routes that are forecasted to be most cost-effective among the potentially newly installed ones in the reference year of the study. Also in the consequential model therefore not a single, short-term or long-term marginal process should be modelled but a mix of the most likely marginal processes, resulting in much more robust models. This is especially important if the various most likely marginal processes have a similar, not significantly different cost competitiveness and at the same time their environmental profile is significantly different


To restrict the model to a single marginal process or system is only justifiable if there are no other, similarly cost-competitive processes or systems and hence the use of a single one is more appropriate. 7.2.4.5 Further aspects, recommendations, and observations Various items If the market is close to or at the border between slightly and strongly declining, it is recommended using the average market consumption mix. Note that these cases are identical to attributional modelling of the main system. Note that all the above also applies when the extra supply is partly or fully unused (e.g. deposited) or undergoing low-value uses (e.g. waste incineration with energy-recovery). These processes contribute to the marginal mix. Analogously, if the analysed extra demand uses otherwise partly or fully unused functions (e.g


waste incineration with energy-recovery). These processes contribute to the marginal mix. Analogously, if the analysed extra demand uses otherwise partly or fully unused functions (e.g. originally deposited or incinerated waste), the “avoided waste treatment”, if any, is credited to the using system.All interim steps 124 Reasons are among others that different actors seem to identify different technologies as the most costcompetitive ones and hence implement not all the same. And then there are issues of patents and available knowledge/experience on technologies or raw material routes etc. by the different actors, as well as political or society constraints and strategies (e.g. "coal power, CHP natural gas, or nuclear power for electricity baseload?").


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results from the generation of the end-of-life product or waste to the secondary good(s) (e.g. sorting, purification, transport, etc.) are to be modelled inside the system boundaries until the quality of the to-be-substituted co-function is actually replacing the superseded processes. In the case of "closed loop" and "open loop - same primary route" recycling, and if the substitution is not equal 1:1 (e.g. due to down-cycling), the actually substituted amount should be credited. If the specific substituted processes are not known or the amount cannot be quantified, market value correction should be applied to the superseded processes‟ inventories. The correction factor is hence the ratio of the market prices for the secondary good versus that of the same amount of the primary good


The correction factor is hence the ratio of the market prices for the secondary good versus that of the same amount of the primary good. Indirect land use changes - overview Indirect land use changes (ILUC) are an aspect under consequential modelling. This issue refers to the situation that an additional demand for land, e.g. to produce a crop-based biofuel, means that the crop that would be produced otherwise on this land has to be produced elsewhere, it is "displaced". The assumption behind this is that additional production of e.g. the biofuel does not change the total amount of other crops produced globally or in that region, i.e. is in addition on a net basis. As the land where that other crop now needs to be produced is also producing something else, ultimately former un-used land (i.e. nature, fallow) needs to be transformed to produce that "displaced" crop. I.e


nature, fallow) needs to be transformed to produce that "displaced" crop. I.e. the additional demand for biofuel is assumed to result in indirect land use changes elsewhere (see also the related example in footnote 20). This is a primary consequence of the type (a) listed in chapter 7.2.4.2. One example for secondary consequences is that the marginally increased price of the displaced crop (and potentially to some degree even of land intensive goods in general) might be an incentive for achieving higher yields by use of more fertilisers and better management. This might partly off-set/reduce the need for an indirect land use change and less land needs to be changed elsewhere than the amount now used for the biofuel. At the same time is it necessary to consider the different productivity of the used and the indirectly changed land e.g. may the "displaced" crop have had a harvest of 5 t per ha on the land now used for biofuel, while the indirectly changed land of e.g


may the "displaced" crop have had a harvest of 5 t per ha on the land now used for biofuel, while the indirectly changed land of e.g. rainforest may yield only 3 t per ha, i.e. more than one ha is necessary for each ha from which the former crop is displaced. Note that in the logic of consequential modelling this applies to all land uses, including food production, industrial plants, private homes etc., whenever a decision support is intended with the study. Indirect land use changes in consequential modelling As no widely accepted provisions exist for indirect land use, but such are still under development by several organisations, no specific provisions are made at this point. The appropriate way how to integrate indirect land use changes is hence to be developed for the specific case, in line with the general provisions o consequential modelling. This is unless specific provisions would be published under the ILCD. Such provisions might be part of a future supplement.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 7 Life Cycle Inventory analysis - collecting data, modelling the system, calculating results 7.2.4.6 Solving multifunctionality of processes in consequential modelling (Refers to aspects of ISO 14044:2006 chapter 4.3.4.2) Introduction Multifunctionality in consequential modelling is solved - somewhat similarly as in attributional modelling - in a two-step procedure next to subdivision / virtual subdivision. The preceding step (subdivision and virtual subdivision) is identical, with one exception: partial subdivision that cuts through a multifunctional process should be avoided as it renders the substitution (see below) distorted. The first step, if subdivision and virtual subdivision are not possible or feasible, depends on the question whether the amount of the co-functions can be entirely independently varied. Details see below


Details see below. Subdivision and virtual subdivision For subdivision and virtual subdivision of black box unit processes the related provisions of chapter 7.4.2.2 apply analogously for consequential modelling. The logic is that the additional amount of the not required co-function can be assumed to be counteracted by changing the production scheme of the other plants that produce the same co-functions so that the total amount of all of them is unchanged. Note that under consequential modelling, virtual subdivision shall not be done if it "cuts" through a physically not subdividable multifunctional joint process. This would distort the substitution


Note that under consequential modelling, virtual subdivision shall not be done if it "cuts" through a physically not subdividable multifunctional joint process. This would distort the substitution. Physical causality in case of true combined production, substitution for joint production In the case subdivision and virtual subdivision are not possible or feasible, the next step depends on the question whether the multifunctional process is a case of combined production or of joint production: if the amount of the co-functions can be entirely independently varied without changing the production facilities, this is called combined production. Examples are most cases of multi-waste incineration, combined transport of different goods. If this is not the case, this is called joint production Examples are NaOH and Cl2 production by electrolysis of NaCl, production of wheat grains and wheat straw


If this is not the case, this is called joint production Examples are NaOH and Cl2 production by electrolysis of NaCl, production of wheat grains and wheat straw. Note that many processes that appear to be combined processes are in fact not fully variable without changing the installed capacity or the nature of the processes, often at high costs (e.g. refinery with its many products that can be varied only to a certain extent without resulting in the need to install additional production plants, purchase external hydrogen, etc.). For true combined production, the determining physical causality (i.e. the first of the two steps of allocation under attributional modelling) equally applies. For joint production, substitution as a special case of system expansion is the solution to multifunctionality. This is drawing closely on the provision for general consequential modelling. This is detailed in the further parts of this chapter


This is drawing closely on the provision for general consequential modelling. This is detailed in the further parts of this chapter. Joint production - substitution in general cases of multifunctionality For the primary consequences of solving multifunctionality via substitution (primary consequence "(b)" of above chapter 7.2.4.2), the same provisions apply as detailed in the preceding chapter on the primary consequences "(a)". Methodologically these cases are equivalent to general consequential modelling, as also acknowledged in ISO 14044:2006. There are however a few, practical differences of relevance to consider, that can in principle also occur in general consequential modelling, but