Definitions and formulas that keep engineering conversations aligned.
Quick technical references for reliability, maintenance, availability, life data, planning, and MRO calculations.
Duane growth formulas
Test time, slope, cumulative, and instantaneous MTBF.
Accelerated testingAccelerated life testing formulas
Arrhenius, inverse power, temperature-humidity, and thermal-cycle factors.
MaintenanceMaintenance KPI formulas
MTBF, MTTR, backlog, OEE, and ROI.
AvailabilityAvailability definitions
Inherent, operational, and production boundaries.
Life dataWeibull parameters
β, η, reliability, and hazard rate.
MROMRO inventory formulas
Lead-time demand, stock, EOQ, and turnover.
Work managementMaintenance planning metrics
Definitions for compliance, work mix, direct labor, and estimates.
Maintenance dataCMMS data quality fields
Definitions for asset records, work-order closeout, codes, and migration evidence.
Fault investigationIntermittent fault and NFF data fields
Definitions for event evidence, service-history ratios, patterns, and reproduction plans.
MRO forecastingIntermittent demand methods
ADI, CV², Croston, SBA, TSB, backtesting, censoring, and FVA.
Operating exposureOperating profile analysis methods
State duration, time at load, threshold excursions, and rate of change.
Definitions are part of the result.
Formula names can look identical while data boundaries differ. Use linked tools and guides to see assumptions before comparing a value across teams or sites.