Track 3 Session 5

8:00 to 9:00 a.m. Wednesday, June 17, 2010

It’s Not Just a Number: The Application of Reliability Analysis in Real World Design

Too often, even in high reliability space applications, the reliability analysis is a chore performed near the end of the design cycle to create a meaningless number that is dropped into an even larger reliability analysis. The main goal is to check off a contractually required deliverable and move on. I have actually heard a designer in a design review joke about what number did the panel want it to be. Reliability analysis is a tool that should be applied early in the design phase, ideally estimated during Phase A and proposal efforts. The results of that analysis can then be used to support system level architectural decisions and ultimately feed other analyses such as the FMEA and probabilistic risk assessment. It can even be used to support make/buy decisions. This presentation argues that parts count reliability analysis is more than a silly number reported at the critical design review and is actually a tool that, when properly asserted, provides cost savings, risk reduction and an optimal high reliability design. In general, the presentation is a light-hearted, slightly irreverent look at reliability analysis with some serious conclusions.

Key Words: Parts Count Reliability Analysis, Probabilistic Risk Assessment, Failure Modes, Effects, Criticality Analysis

Michael Epperly

Southwest Research Institute

San Antonio, Texas