中文摘要：

本文研究由两不同型部件组成的冷贮备可修系统的最优化更换策略问题．在该系统中，修理工可多重休假且修理设备具有优先权．通过引入一类推广的泊松过程来模拟系统的运作状态，并结合新定义的更换周期，从理论上找出该系统经长期运行单位时间的期望损失的具体表达式．最后，通过事例，从直观上验证文中所涉及到的一些理论结果．

英文摘要：

In this paper, we study a cold standby repairable system with one repairman who can take vacations. The system consists of two different components, in which one component has priori- ty in use and repair. We quote an extended Poisson process （EPP） to describe the working state and the repair state of component 1,and consider a new replacement policy N based on the failed times of component 1 and the repair situations of component 2 at the end of a renewal cycle. The explicit ex- pression of the expected cost rate is derived, and the corresponding optimal replacement policy N＂ can he determined numerically. Finally, several numerical examples are given to illustrate the theo- retical results of the model in this paper.