Dynamic maintenance in series - parallel manufacturing systems with consideration of buffer inventory

A lot of preventive maintenance models have been developed for single machine. Also, in some of preventive maintenance models, the PM intervals are considered constant for all of the periods and most of developed maintenance models are focused on the cost. The preventive maintenance activities resulted in a certain cost and time that often required to stop the production line. In this case, it would be better to provide a model for coordination of production planning and maintenance. In this paper, development of a model which is suitable for determining the dynamic (considering machine status in each cycle) optimal interval for preventive maintenance operations is considered in series - parallel systems by using of multi objective decisions methods. Also for reduction of stopping the production line, assuming the buffer is added to the model and the optimal buffer size will be determined by the model. In this case, No damages will be made in production planning while performing maintenance operations on each machine. Conclusion of this paper is determining the dynamic optimal interval with consideration buffer. At the end, performance of the method is demonstrated by solving a sample problem.