Reference desk

Definitions and formulas that keep engineering conversations aligned.

Quick technical references for formulas that recur in reliability, maintenance, availability, life data, and MRO planning.

Maintenance

Maintenance KPI formulas

MTBF, MTTR, backlog, OEE, and ROI.

Availability

Availability definitions

Inherent, operational, and production boundaries.

Life data

Weibull parameters

η, β, reliability, and hazard rate.

MRO

MRO inventory formulas

Lead-time demand, stock, EOQ, and turnover.

Definitions are part of the result.

Formula names can look identical while data boundaries differ. Use the linked tools and guides to see assumptions before comparing a value across teams or sites.