The main objective of the present study is to analyze a single-unit system under the concept of preventive maintenance, inspection, degradation and replacement. For this purpose, a stochastic model of single unit has been developed. The repair and preventive maintenance of the system are affected by abnormal environmental conditions, while replacement and operative original/degraded unit remain unaffected. The system does not remain as new after repair. A single repair facility is provided to the system as and when required for performing various repair activities. After, a pre-specific time ‘t’ repairman takes the unit under preventive maintenance. The system is inspected by the repairman upon failure to check the feasibility of repair and replacement. All failure and repair time distributions are arbitrarily distributed like Weibull distribution with common shape parameter and different scale parameters. Recurrence relation for various system-effective measures has been developed by using SMP and RPT. The numerical values for MTSF, availability and profit have been obtained for the interest of system designers.

中文翻译：

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在不同环境条件下进行检查和降解的单机系统的随机建模

本研究的主要目的是在预防性维护，检查，降级和更换的概念下分析单机系统。为此，已经开发了单个单元的随机模型。系统的维修和预防性维护会受到异常环境条件的影响，而更换和可操作的原始/降级单元仍不受影响。修复后，系统不会保留为新系统。当需要执行各种维修活动时，将单个维修设施提供给系统。之后，具体的预时间'牛逼修理工对设备进行预防性维护。发生故障时，维修人员会检查系统，以检查维修和更换的可行性。所有故障和维修时间分布都可以像具有相同形状参数和不同尺度参数的威布尔分布那样任意分布。通过使用SMP和RPT已开发出各种系统有效措施的递归关系。为了系统设计人员的利益，已经获得了MTSF，可用性和利润的数值。