Optimality of Control-Limit Type of Software Rejuvenation Policy

Software rejuvenation is a preventive and proactive maintenance policy that is particularly useful for counteracting the phenomenon of software aging. In this paper we consider an operational software system with multiple degradations and derive the optimal software rejuvenation policy minimizing the expected operation cost per unit time in the steady state, via the dynamic programming approach. Especially, we show analytically that the control-limit type of software rejuvenation policy is optimal. A numerical example is presented to make a decision table and to perform the sensitivity analysis of cost parameters