Research On Integrated Scheduling Algorithm Considering Equipment Maintenance

Integrated scheduling is a scheduling problem that studies how to process the processing and assembly of complex single room products in parallel.The past integrated scheduling problem is usually assume that processing equipment is always available before processing all the process,however,in the actual production process,equipment loss is inevitable,leading to lower production efficiency,therefore,equipment maintenance activities becomes an integral part of the manufacturing process.Under this background,this paper studies the integrated scheduling problem with equipment maintenance constraints.Aiming at the integrated scheduling problems with settled maintenance time,this paper proposes an algorithm of the integrated scheduling with maintenance time,this algorithm converts this problem into 0-1 knapsack problem,uses the equipment classification strategy to form a procedure set for scheduling from the leaf node of the process tree and uses long path priority strategy to schedule the process which has longer path preferentially.Examples show that this algorithm have better performance than greedy strategy.Aiming at the integrated scheduling problems with interruptible process,this paper proposes a strategy determining schedulable procedure set based on the process feature.According to the features of interruptible process,which can start in any available period of equipment,scheduling the general process preferentially,insert the interruptible process in spare time before maintenance activities start,so as to make full use of the idle time of equipment,the examples show that this algorithm can shorten the equipment idle waiting time effectively,make process more compact,and shorten the overall processing time of the product.Aiming at the integrated scheduling problems with adjustable maintenance starting time,define a constant named maximum overload running time for equipment,then using dynamic programming method to form a procedure set for scheduling,which can minimize the gap between completion time and scheduled maintenance time,using APCM,short-time first strategy and Layer priority strategy to determine the scheduling sequence,determine the actual equipment maintenance time according to the overload running time.Examples show that this algorithm can reduce the equipment overload running time and shorten the total processing time.