Interval Type-2 Fuzzy Flexible Job-Shop Dynamic Scheduling Considering Variable Remaining Processing Capacity

As for disturbance issues in flexible job shop, such as machine breakdowns and uncertain processing time, the model of the aim of minimize completion time and minimum total cost is built in this paper. Meanwhile, proposed two different and effective ways to solve both issues. First of all, considering variable remaining processing capacity of the broken machine to against the effects of machine breakdowns, which also can increasing the utilization of the broken machine fully. Secondly, in order to suit complex environment of workshop, the processing time of operations is described by interval type-2 fuzzy. In terms of algorithm, two improvements are proposed, which are using three different approaches generating initial populations to improve the quality of initial solutions and proposed a spiral mutation strategy to jump out of the local optimal timely. By a experimental example, the frontier solutions obtained by the improved NSGA-II algorithm has higher quality and better distribution in both global and local optimization, which proved validity of improvements.