Integrated Scheduling Algorithm Based On Event-Driven By Machines' Idle

Aiming at the problem that determining the scheduling sequence according to the length of path by the integrated scheduling algorithm based on allied critical path method will cause parallel processing among the groups of operations and machines with plenty of idle time, this paper presents an integrated scheduling algorithm based on event-driven by machines'idle. Selecting operations which need be processed according to the idle machines is the main method in this algorithm. Process of this method is to regard the end of each operation processed as an event with machines'idle, and this event drives idle machine to search schedulable operations. If schedulable operation is sole, this operation is scheduled. If schedulable operations are not sole, the operation whose father node has longest path length is selected. If the operations with longest path of father node are not sole, operation whose processing time is shortest is selected. As this algorithm doesn't think about the operation sequence while scheduling operations and it is driven by machines'idle, the algorithm can cause among schedulable, take full advantage of idle time of machine and avoid problem that there will be more machine idle time by using the integrated scheduling algorithm based on allied critical path method. In addition, the algorithm doesn't need to compare the length of machine idle time and judge whether using identical machines is balanced, and also not need idle machine to detect schedulable operations frequently, so plenty of judgment operations can be saved. Examples show the algorithm which is proposed not only has the highest efficiency than other algorithms based on allied critical path method, but also be easy to realize.As the situation record by scheduling system is just the instant situation of product's processing and the global analysis of production has been ignored, this paper occupies the event idea to solve integrated scheduling problem as well as analyzing globally for event-driven. Use the completion of each procedure as a searching event of schedulable procedures. Through analysis of rollback- preemptive, adopt rollback event to reschedule if the new schedulable procedure has ability of grab, and then make global optimized judgment for procedures scheduled which have been chosen.Aiming at the dynamic scheduling problem, non-close-joining problem and problem with same machine which emerge in integrated scheduling problem, the traditional solving method relies on ACPM. Use event-driven idea proposed by this paper to resolve these problem. Through analyzing examples'result, this algorithm not only has better time complexity, but also the scheduling results are better than traditional algorithms. So the algorithm in this paper has theoretical and practical value.