A Summary of Replacement Policies with Number of Failures

Abstract

Periodic replacement models with minimal repairs have been studied extensively. In order to prevent high repair costs after failures, this paper considers the number of failures as another decision variable for replacement policies. We begin with the standard periodic replacement model, and then summarize several extended replacement models with number of failures, using the respective assumptions of whichever occurs first and last, and replacing over planned measure, respectively. Optimum policies of replacement times T, number of periodic times N, and number of failures K are discussed analytically. From the optimization of the integrated models of T, N and K, comparisons among these policies are made in analytical ways to determine which policy should be more economical.

Keywords

• Minimal repair
• Periodic replacement
• Replacement last
• Random failure
• Cumulative hazard rate.