A reliability demonstration test plan derivation method based on subsystem test data

Abstract

A reliability demonstration test (RDT) has been used to determine whether a product meets pre-specified reliability requirements and to decide whether a batch of products should be accepted or rejected. For systems with high reliability, standard RDTs are no longer preferred because test plans often require long test durations and pose high risks to producers and consumers. Related reliability information, such as subsystem test data, which is often available prior to system testing, is often neglected. For the widely applied assumptions of exponentially distributed subsystems and systems, this paper proposes a reliability demonstration test plan derivation method that makes use of subsystem test data to derive the probability density function of system failure rate for small-sized sample data. In comparison with conventional RDT plans that make decisions solely based on system test data, a system test plan can be derived with much shorter test durations while keeping producer and consumer risks under control. The case study shows that our proposed method can reduce risk and shorten test duration when a test plan needs to be derived for a system with subsystem test data.