On missions’ quality of performance for systems with partially or completely observable degradation

Abstract

At some instances, it is better to terminate operation of a system than to wait for its failure or completion. However, in this article, we are mostly interested in missions that are cost-effective during the whole mission time and, therefore, do not require termination. Moreover, some requirements for parameters of the considered models that guarantee this cost-effectiveness are analyzed. We consider two failure models for systems executing missions of the fixed duration. In the first model, degradation is partially observed via the number of shocks experienced by a system. Shocks act directly on the failure rate forming the shot-noise process. In the second model, degradation is completely observed and is modeled by the Poisson process. Thus, the number of shocks or the number of failed components is the degradation parameters in our models, respectively. The detailed numerical examples illustrate our findings. Specifically, the bounds for the number of events (shocks or component’s failures) observed at each instant of time that guarantee cost-effectiveness of a mission are obtained.