Preventive Maintenance Models for Technical Systems

There are analysed and summarized the results of preventive maintenance, one of the most commonly used maintenance strategy. The reviewed literature is classified into two main groups of models for one-unit and multi-unit systems. For single-unit systems the author investigates age-replacement policies, block-replacement policies, sequential preventive maintenance policies, failure limit policies and repair limit policies. The optimum policies are discussed, and their several modified and extended models are presented. The main extensions include imperfect maintenance implementation, shock modelling, or finite/infinite time horizon modelling cases. The classification also includes optimality criterion and used modelling method. For multi-component systems maintenance case there are analysed the main replacement policies for systems with and without components dependence. First, the simplest models are analysed, i.e. age-replacement and block-replacement policies. Later, the maintenance policies for systems with components dependence are introduced. The author summarizes the latest developments for group maintenance, opportunistic maintenance, and cannibalization maintenance models. The discussion of models bases on criteria, among others, planning horizon, modelling method, and optimization criterion. The main development directions in preventive maintenance modelling are presented in a graphical form. The brief summary of the conducted literature review is provided with indicating the main research gaps in this modelling area.