A competing risks model with degradation phenomena and catastrophic failures

This paper proposes a competing risks model for the reliability analysis of units subject both to degradation phenomena and catastrophic failures. The paper is mainly addressed to the analysis of real data presented in Huang and Askin (2003) which refer to some electronic devices subject to two independent failure modes. The first mode is the light intensity degradation, which is treated as a degradation phenomenon since the light intensity is observed and measured at given inspection times. The other failure mode is the solder/Cu pad interface fracture, which is classified as a catastrophic failure. The main reliability characteristics, such as the probability density functions and the cumulative distribution functions of each failure mode in the presence of both modes, are estimated. Likewise, the estimate of the hazard function, of the unit reliability under the competing risks model, and of the proportion of failures caused by each failure mode are derived.