Reliability
Reliability is the probability that an item performs its intended function without failure for a specified interval under stated conditions. Numerically, it ranges from 0 to 1, where 1 represents failure-free operation. It is calculated via the formula R(t) = e^(-λt), where λ is the failure rate (equal to 1/MTBF) and t is the time duration.
In a CMMS like ServiceGrid, reliability is operationalized by maintaining a complete asset register with criticality classification, a failure mode library, and a PM library tuned to those modes. It requires tracking MTBF and MTTR on top critical assets to measure asset health and efficiency. Reliability engineers use CMMS historical data (work orders, failure codes, repair durations) to identify recurring patterns, calculate actual MTBF, and design maintenance intervals aligned with degradation patterns rather than arbitrary schedules.
How does reliability differ from availability?
Reliability is the probability of failure-free operation over time t; availability is the proportion of time a system is operational at a specified moment or interval, incorporating both reliability and maintainability.
What is the relationship between MTBF and reliability?
MTBF is the inverse of the failure rate (λ = 1/MTBF); reliability at time t is R(t) = e^(-t/MTBF).
Why is CMMS data critical for reliability engineering?
Without reliable CMMS data on work orders and failure codes, analysis rests on assumptions rather than evidence, preventing accurate MTBF calculation and effective maintenance strategy design.