FMEA-based DEMATEL apportionment approach

Reliability allocation is one of the most important tools to improve system reliability, which totally influences product life cycle costs and system operational effectiveness. However, most reliability allocations methods often neglect many important features, such as maintainability and risk and do not consider indirect relations between subsystems or components. In this paper, an effective reliability allocation methodology has been developed using a system failure mode and effects analysis (FMEA) and decision-making trial and evaluation laboratory (DEMATEL) technique, which considers severity of failure, occurrence of a failure, and detection of a cause of failure in reliability design. It is an easy and effective approach, which uses system FMEA to determine subsystem allocation weighting factors and then uses the DEMATEL technique to consider the inter-relationships between subsystems and apportion reasonable reliability ratios into subsystems or components. This study evaluates reliability allocation in the context of a fighter aircraft engine data acquisition unit (EDAU). The results from comparison with traditional reliability methods show that the proposed method is both accurate and realistic.