SUMMARY
Reliability optimization of manufacturing systems is important for saving cost and improving productivity. Maintenance optimization, as a backward reliability optimizing strategy to certain manufacturing systems, has been the research focus in reliability engineering. This paper proposes a forward reliability evaluation and optimization method to reduce failure effects in the initial stage of process planning from the source of system construction formation. In this paper, reliability calculation of machines is closely related with its operation states, based on which an event graph is used as the system reliability analysis model. Subsequently, system reliability is surveyed under different stages of the system’s lifespan, it is inferred that reliability based process planning is of great importance for efficiency growing of failure-prone manufacturing systems in the later stages of the lifecycle.