docs/LIMITATIONS.md

Sofia Engine Operating Boundaries & Transparent Limitations

In accordance with our engineering principle "Evidence beats claims", the following boundaries and limitations apply to Sofia Engine 3.0.0a1:

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1. Checkpoint Distribution Status

• No Canonical Pretrained Foundation Model: Sofia Engine 3.0.0a1 is a Scientific & Edge Intelligence Runtime, not a foundation model. No pre-trained neural checkpoint is distributed in this initial release. Future trained checkpoints (e.g. bearing fault classifiers, transformer-based time-series anomaly models) will be distributed with explicit training provenance, evaluation reports, and SHA-256 digests.

2. Hardware & Fixed-Point Numerical Differences

• C99 vs. Python Floating-Point: The Python runtime operates in IEEE 754 double precision (64-bit float). The C99 embedded reference engine supports both single precision (32-bit float) and Q16.16 fixed-point arithmetic. Fixed-point computations have a finite resolution of $\approx 1.526 \times 10^{-5}$ and may exhibit small truncation differences compared to 64-bit float baselines.

3. Standards Compliance Scope

• Relevance vs. Formal Certification: Sofia Engine implements calculations relevant to industrial standards (e.g., ISO 10816/20816 vibration severity zones, IEEE 519 harmonic limits, IEC 61000-4-30 power quality concepts). Software implementation does not constitute formal device or system-level certification. Certified deployments require end-to-end hardware calibration and formal test laboratory certification.

4. Operational Safety Notice

• Non-Replacement of Qualified Engineering Judgment: Diagnostic outputs (Health Scores, Severity classifications, Anomaly events) are mathematical inferences based strictly on incoming sensor telemetry. They do not replace certified human inspection or qualified engineering judgment.
• Physical Safety Interlocks: Sofia Engine outputs must never be connected directly to emergency stops, circuit breakers, or critical plant actuators without independent, hardwired, safety-certified physical interlocks (e.g. SIL-rated safety relays).