Reliability tools enable strategic problem resolution & savings

This paper presents a case study depicting the use of a number of Reliability Tools following the: Define, Measure, Analyze, Improve, and Control (DMAIC) process to attain gains. A Failure Reporting Analysis and Corrective Action System (FRACAS) database is used to identify (hardware failure / program money) problems. A well-defined FRACAS database with a solidly defined root cause classification is shown to be a strong asset in identifying the alignment issue. Physics of Failure (PoF) is used in the root cause analysis of Environmental Stress Screening (ESS) failures. The PoF provides a science-based approach to the understanding of the interaction, or physics, between the various electrical and optical components in specific ESS environments. The driving factors behind the failures are revealed to be the result of mechanical stresses induced/relaxed by thermal cycling. The justification of the solution requires the acknowledgment of the common supposition that problems discovered late in the production process are substantially more costly to fix than if discovered earlier. A cost benefits analysis is used to justify action of adding a completely new thermal cycling step early in the production process at the sub-assembly level. Design of Experiments (DOE) assists in identifying the type of thermal cycling to implement. The case study closes with a verification of the benefit of early problem identification with pre and post process change data. Reliability is not just the math and statistics, it is also solving problems and saving money.