Research On Integrated Scheduling Algorithm Of The Multi-procedures Ended Together

For the multi-product of small quantities of products, especially the single complex products, if manufactured according to the previous method which is processing first and assembly last. The parallel relationship between processing and assembly is inevitable separated. So the third scheduling method:the integrated scheduling which processing and assembly are dealt together has been proposed.Integrated scheduling problem is a problem which is to make procedures’ processing and assembly are dealt together, namely the assembly part is called a special processing part, and there is no situation of pure processing and pure assembly. Under meeting certain constraints, integrated scheduling can reasonably allocated the processing machine and the assembly machine, arrangements for scheduling time reasonably, then make the scheduling result more optimize.There are usually the demand of multiple-process which ended at the same time in the actual production, as if the processing quality of some procedures do not meet the requirements, the product assembly can not carry on, which can affect the production process or cause the problem of large economic losses, in order to avoid these problems, for certain processing procedures which completed processing and through coordination detection before subsequent procedures processing, therefore it is necessary to study the integrated scheduling with the constraints of multiple-process which ended at the same time. Aiming at this problem, the procedures with the constraints of multiple-process which ended at the same time is defined as virtual procedures, and the virtual procedures with the constraints of multiple-process which ended at the same time is defined as virtual process group. In order to get a better scheduling result, three solutions have been proposed:①Determine the overall critical path of the product technology tree, the procedures after the virtual process group and the subtree of the virtual process group is scheduled using the allied critical path method;②For the product processing tree, respectively calculate the critical path of the procedures after the virtual process group and the subtree of the virtual process group, and then determine the scheduling order according to allied critical path method.③For the product processing tree, the virtual procedures, the procedures before the virtual procedures, and the procedures after the virtual process group is divided into three parts, respectively determine the critical path of the procedures before the virtual procedures and the procedures after the virtual process group. the scheduling the procedures before the virtual process group using the allied critical path method according to multi-products scheduling, then determine the finish time of the virtual procedures, at last, scheduling the procedures after the virtual procedures according to the allied critical path method according to single product scheduling.These three algorithms proposed in this paper can solve the integrated scheduling problem with the constraints of multiple-process which ended at the same time, and the scheduling results are getting much better. Through example validations, the proposed algorithm have lower complexity and easy to achieve. therefore the proposed algorithm have both theretical value and practical value, it has certain value to further study integrated scheduling problem with the constraint of multiple-process which ended at the same time.