Reliability Analysis is defined as the probability that a given system will perform its function adequately for its specified period of a lifetime under specified operating conditions.
Reliability Analysis Common measures are :
1. Failure rate.
2. Mean time between failures(MTBF)
3. Survival percentage.
The rate at which components of the population fail.
Ns(t)- No. of components that survived during time ’t’
Nf(t) – No. of failures that occurred during the same time.
Mean time between Failures(MTBF):
The reciprocal of the failure rate(1/λ).
λ —-Failure rate.
Failure rate = (No.of failure )/(Time period during all components were exposed to failure)
Failure Mode and Effect Analysis(FMEA)
The purpose of FMEA:
- To recommend design changes.
- To identify design weaknesses.
- To help in choosing alternatives.
Four Stages of Reliability Analysis:
Ist Stage – System boundaries and the scope of the analysis are decided.
IInd Stage – Data Collection
Ex: Specification, Operating Procedure, Working Conditions.
IIIrd Stage: Preparing the component or parts list.
IVth Stage – Failure frequency and the functions of the part identified, causes of failures, Failure detection.