Research On Integrated Scheduling Algorithm With Multiple-Devices-Operation Of Complex Product

Integrated scheduling is mainly study on how to make processing andassembling of complex single products efficiently parallel processed. Efficientand reasonable scheduling plan can shorten production cycle and bring greatereconomic benefits.Determining the scheduling sequence according to dynamic long-pathstrategy, the start time of essential schedule operation may be later than start timeof the other schedulable operations on the same device, which will causeextension of product’s total processing time. An integrated scheduling algorithmbased on dynamic essential path’s end time is proposed. Because the proposeddynamic early end essential path strategy in this paper taking into account the endof the following operation as early as possible, can shorten product’s totalprocessing time.Aiming at integrated scheduling problem with multiple-devices-operation, amethod to change multiple-devices-operation into multiple related virtualoperations which processed on multiple related machines at the same time isproposed. This algorithm uses the virtual processing tree, on which eachmultiple-devices-operation is changed into a virtual operation group, anddecomposes the virtual processing tree for the subtree whose root node is virtualoperation group and subtree that composed of remaining standard operations. Thesubtree whose root node is virtual operation group is scheduled previously; Whenthe subtree whose root node is virtual operation group is not unique, determinesthe scheduling order of the subtrees according to the number of virtual operationgroup on them, and determines the scheduling order of operations on subtreewhose root node is virtual operation group according to the number of virtualoperation group on the path. In order to make related virtual operations start atthe same time，virtual operation dynamic adjustment strategy is proposed. Aiming at the previous integrated scheduling problem with multiple-devices-operation didn’t considered essential path’s end time of schedulableoperations on the same device, which may cause extension of product’s totalprocessing time, an integrated scheduling algorithm with multiple-devices-operation based on layer priority strategy is proposed. Considering thatmultiple-devices-operation needs multiple devices, that is demand for device ishigher, multiple-devices-operation is scheduled previously; the scheduling orderof standard operations in which related operation group and the remainedstandard operations are confirmed by dynamic allied critical path strategy anddynamic early-end essential path strategy. The algorithm can not only optimizeintegrated scheduling algorithm with multi-devices-operation but also do notincrease the time complexity of the algorithm. Finally, the superiority of thealgorithm is demonstrated by example analysis.