Agent skill · vasilyu1983
foundations-reliability-theory
Reliability-theory primitives for MTBF/MTTR, availability, hazards, FMEA, redundancy, error budgets, Weibull analysis, and SLOs. Use when modeling failure.
What it needs
About 11k tokens when loaded.
What this skill does
Reliability Theory Foundations 11 reliability theory primitives covering the mathematics of failure, availability, and repair. Each primitive is domain-agnostic: the same MTBF/MTTR arithmetic that governs hardware maintenance governs SLO budget calculation; the same fault tree that maps a safety system maps a payment pipeline's SPOF paths. Contents Quick Reference Primitive Index Formal Supporting Theory Misuse Boundaries Anti-Patterns Decision Checklist Composition Recipes Expert Judgment: When the Math Lies Workflow ASCII Flow Navigation Related Skills Fact-Checking --- Quick Reference # Primitive When to Reach for It --- ----------- --------------------- 1 MTBF / MTTR Measuring how often a system fails and how long it takes to recover 2 Availability Formulas Converting MTBF/MTTR into a percentage; composing series and parallel components 3 Hazard Functions Classifying current failure rate shape (constant / increasing / decreasing) 4 Bathtub Curve Identifying the lifecycle phase (infant mortality / useful life / wear-out) 5 Fault Tree Analysis Tracing a top event backwards to root causes; finding single points of failure 6 FMEA Enumerating failure modes bottom-up and ranking by RPN before launch 7 Redundancy Math Sizing active/standby/k-of-n redundancy; checking coverage sensitivity 8 Error Budgets Deriving SRE error budget from SLO; computing multi-window burn rate 9 Weibull Analysis Fitting lifetime data to a distribution; estimating B10 life and phase 10 System Reliability Combining component reliabilities through series/parallel/mixed topologies 11 Reliability Allocation Apportioning a system reliability target to subsystems --- When to Apply Apply reliability-theory when: SLO design or error-budget math (availability targets, allowed downtime, burn rates) Redundancy decisions — single instance vs active-active vs N+1 vs geographic FMEA / fault-tree analysis on a system before launch or post-incident Hazard-rate questions — "is this an infant-mortality bug, ra …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills vasilyu1983/foundations-reliability-theory