Accelerated Life Test Plans for Repairable Systems With Multiple Independent Risks

This paper proposes a Bayesian approach to planning an accelerated life test (ALT) for repairable systems with multiple
s
-independent failure modes. A power law process (PLP), that combines both proportional intensity (PI) and acceleration time (AT) approaches, is used for modeling the failure process of repairable systems under ALT. Based on the Bayesian
D
-optimality, and
Ds
-optimality, we develop optimal plans for ALT by invoking the general equivalence theorem. We also discuss the elicitation of prior distributions, and derive the expression of the Fisher information matrix. Finally, a case study on testing diesel automotive engines is presented to illustrate how to use the proposed planning principle to obtain the 2-stress-level optimal plan, and a compromise plan for 3-stress-level ALT.