neqsim-technology-fmirr

Technology FMIRR (Failure Mode Identification and Risk Ranking)

Use this skill to keep and rank the failure-mode register of a technology that is being qualified. The register is the basis for defining and prioritising the qualification activities: every critical failure mode must trace to a qualification activity (the TEST column) and every re-rating must trace to evidence.

When to Use

• After neqsim-technology-assessment has identified novel elements (category 2b-4) and before the qualification plan is written.
• To prepare or review the output of an FMIRR workshop with an expert panel.
• To repeat the FMIRR as test results and mitigations change the risk.
• To feed the FMIRR chapter of neqsim-technology-assessment-report.

It does not replace the workshop. Failure modes, causes and ratings must come from a panel covering the needed disciplines.

Inputs

• technology name.
• entries: one per failure mode with id, item (failed item or component), function, failure_mode, failure_mechanism, failure_mechanism_class, failure_cause, failure_cause_class, detection, consequence_text, consequence_class (1-5), probability_class (1-5), comments, qualification_test (link to the qualification plan), lifecycle_phase, novelty_category.
• Optional: a custom 5x5 matrix and the high-consequence floor setting.

Outputs

• rows with the computed risk (Low, Medium, High) and a critical flag.
• summary: counts per risk level, critical ids ranked, critical modes with and without a qualification test.
• risk_matrix: counts per probability and consequence cell.
• findings: warnings and gaps (mixed terminology, missing mechanism, critical modes without a test or detection, life-cycle phases not covered).
• history: previous ratings with their basis; iteration number.

Engineering Method

1. Scope. Take the novel elements from the technology assessment and their life-cycle phases (design, fabrication, transport, installation, commissioning, operation and maintenance, decommissioning).
2. Identify failure modes per element and phase. Keep four separate fields:
   • Failed item: the component that fails.
   • Failure mode: how it fails (for example external leakage, fails to close).
   • Failure mechanism: the physical process (mechanical, material, instrumentation, electrical, external influence, miscellaneous).
   • Failure cause: why (design, fabrication/installation, operation/maintenance, management, miscellaneous; include human error). Use the equipment-specific ISO 14224 failure-mode tables where they exist.
3. Rate consequence for the system as specified, without safeguards that are not yet adopted. Use the highest class across people, environment, delay/downtime and reputation. Define the scale for the case.
4. Rate probability with qualitative classes early; replace by evidence (tests, analysis, documented experience) as it arrives. If evidence is lacking, be conservative, more so for higher novelty.
5. Rank risk with the matrix. Medium and High are critical and must be covered by the qualification plan. Low modes stay in the register. The high-consequence floor keeps class-5 consequences at Medium or above so that low probability does not dismiss them.
6. Link tests. Give each critical mode a qualification activity and a detection method.
7. Re-rate and repeat. Record the basis for every change, start a new iteration at each qualification milestone, and never delete a mode.