Analysis of Accelerated Life Tests with Intrinsic and Extrinsic Failure Modes

내부고장요인과 외부고장요인이 있는 제품에 대한 가속수명 시험의 분석

This paper proposes a method of estimating the lifetime distribution at use condition for constant stress accelerated lift tests when extrinsic failure mode as well as intrinsic one exists. A mixture of two log-normal distributions is introduced to describe these failure modes and it is assumed that a linear relation exists between the location parameter and stress. An estimation procedure using the expectation and maximization algorithm is proposed and a numerical example is given.