Dynamic availability and performance deficiency of common bus systems with imperfectly repairable components

Abstract

Common bus performance sharing (CBPS) abounds in diverse applications such as transportation, power supply and collaborative computing to facilitate efficient utilization of limited system resources. This paper models such a CBPS system with repairable components performing the main system function and repairable bus lines for redistributing surplus performance of some system components to components undergoing performance deficiency. Both time-to-failure and time-to-repair of system units (including components and lines) are random and may follow any arbitrary types of distributions. A probabilistic model based on discrete-state continuous-time stochastic processes is proposed for evaluating instantaneous availability of these repairable system units. The proposed model addresses the general repair policy encompassing minimal repair, perfect repair and imperfect repair. The universal generating function technique is further implemented for evaluating the system level performance metrics, including instantaneous system availability, instantaneous expected performance deficiency, expected system availability and total expected unsupplied demand during a specified mission time. Examples are provided to illustrate the proposed evaluation methodology and its application in prioritizing maintenance improvement actions.