Vehicle Maintenance Strategy Simulation And Decision-making

Maintenance plays an important role in the safe operation of transportation vehicles, production equipments, military equipments, and so on. Maintenance cost is also one of the major expenditures of enterprises. However, most enterprises have been paid insufficient attention to the maintenance management, and the research on the maintenance management appears relatively little in China. As a result, there commonly exists over- or under-maintenance phenomenon in China enterprises. It is estimated about one third of maintenance cost is wasted. Therefore, it is said that“the maintenance management is the last frontier of operational research”.Currently, the maintenance decisions are mainly based on the experience and qualitative judgment, and the decision-making process is lack of quantitative analysis. In addition, the previous study mainly focuses on single-unit systems rather than multi-unit or multi-item systems. The causes may include the complexity in modeling such complex systems and solving such complex problems.This thesis based on vehicle studies its maintenance strategy simulation and decision-making. Main contents are as follows.Certain size vehicles make up of vehicle fleet. Enterprises or organizations have many different types of vehicle fleets; their comprehensive maintenance management is a complex problem. Based on the literature, the thesis establishes the framework of fleet comprehensive maintenance management in order to supply modules for applying maintenance management software.Vehicle can be considered as a multi-unit system, so Monte Carlo method is used to simulate the performance of multi-unit system, and provide the tool of decision-making analyses. In the meantime, the preventive maintenance is imperfect maintence and two measures of maintenance degree are defined to reflet the maintenance effect of imperfect maintenance close to that of perfect maintenance.Maintenance is based on reliability analysis and the reliability models of components are the basis of that of vehicle. So the reliability model of a key vehicle component is built based on field data, which will be the basis of building reliability models of vehicle and even vehicle fleet. In the meantime, the reliabity model is used in quantitative analysis of maintenance decision-making.