Dynamic Scheduling Problem Of Mixed-flow Production System Considering Urgent Order Interference

Facing the customers personalized dynamic increasing market demand and many varieties,small batch products due to changes in customer orders and complex production environment,manufacturing enterprises need according to the actual situation of production,use of advanced manufacturing technology,develop a kind of both flexible and efficient production scheduling scheme,to improve manufacturing capability,to ensure market competitiveness.Virtual cellular manufacturing system as a kind of advanced manufacturing technology in dynamic production environment to adapt to the good,according to the order task and manufacturing resources,rapid configuration suitable production resources,and according to the real-time change of order to timely adjust resources to ensure that the dynamic scheduling of the flexible and efficiency,can realize in the dynamic scheduling make full use of manufacturing resources,improve the enterprise’s ability to adapt to dynamic market demand and production environment.This paper takes the mixed-flow production system of Plant J as the research object.Using the advanced manufacturing technology of virtual cell manufacturing system,discussing the dynamic scheduling problem of mixed production system for urgent order insertion.The main contents are as follows:(1)Aiming at the production scheduling process of multiple reservation orders at the same time in factory J,the resource scheduling problem of multiple reservation orders arriving at the same time is studied.Based on the theory of virtual manufacturing cell construction,a two-stage virtual manufacturing cell construction method is proposed.In the first stage,based on the theory of resource elements,the process requirements of the ordered products are analyzed and the capability of the equipment group is analyzed to determine the process requirements of the products and the capability boundary of the equipment.In the second stage,the cluster analysis of production and manufacturing resources was carried out to build a nonlinear mixed integer model with the minimum equipment sharing among virtual manufacturing cell and the minimum product process difference within the virtual manufacturing cell.An improved genetic algorithm based on virtual manufacturing cell number coding was designed to solve the problem,and the production resource scheduling scheme for pre-ordered products was obtained.(2)Aiming at the rescheduling process of production planning in a mixed-flow production system after the insertion of urgent orders,the resource and time scheduling problems of all orders in the system were studied.In the first stage,a similarity coefficient method based on product family and equipment group in the virtual manufacturing cell is adopted to judge whether urgent order and scheduled order can be integrated into production according to the insert situation of urgent order in Factory J,and the production resource scheduling scheme after urgent order insertion is reconstructed.In the second stage,according to the reconstructed virtual cellular,a mixed integer model was built to minimize the completion time of urgent order and the total process time of completing all task orders.The solution was solved by the improved genetic algorithm of two-stage coding,and the scheduling and sorting scheme of virtual unit time after the insertion of urgent order was obtained..(3)Verify the validity of the dynamic scheduling model and solution method proposed.In the case of customer order change,the production resource scheduling status of multiple scheduled order arrival and urgent order insertion based on manual experience algorithm in Factory J is deeply analyzed.The model and method proposed in this paper are applied to the short-term production planning and scheduling example of high-frequency product processing workshop in J Factory,Using MATLAB programming to obtain the optimal scheduling scheme.The equipment utilization rate,the equipment equilibrium utilization rate based on resource elements and the system utilization rate are used as the comparison indexes.The results show that the method proposed in this paper has a better effect on optimizing the allocation of production resources and improving the production efficiency compared with the existing methods in enterprises,which verifies the effectiveness and superiority of the proposed method.