New reliability indices for first- and second-order discrete-time aggregated semi-Markov systems with an application to TT&C system

Research on reliability indices has received considerable attention recently in the field of reliability. In this work, two new reliability indices — multi-point bounded-covering availability and multi-interval bounded-covering availability — are introduced for discrete-time systems. Their explicit formulas are derived for discrete-time first- and second-order aggregated semi-Markov systems, whose state spaces are divided into three subsets corresponding to perfect functioning states, imperfect functioning states and failure states, respectively. Finally, some numerical examples are presented to illustrate the developed results. The results established here will also be useful for many practical reliability systems.