Study On Virtual Cell Dynamic Scheduling With The Arrival Of Rush Orders

Virtual cell production is a new kind of cell manufacturing model development and begins to get more attentions in developed counties recently, which becomes popular and causes many domestic and foreign experts and scholars study it. However, to reduce the complexity of the problem, many scholars studying virtual cell scheduling problems don’t consider random disturbance factors and cross-cell case, and just simplify virtual cell scheduling problem as a static scheduling problem within the cell, which ignores the existence of close links between the cells and random disturbance factors. In view of this problem, the article studies virtual cell dynamic scheduling problem with rush order arrival based on the depth study of virtual cell dynamical scheduling research status at home and abroad and related theories.When a rush order arrives, the similarity between the rush orders and the existing virtual cells will be measured. Once the existing virtual cells are not able to meet the production requirements of rush orders, virtual cell reconfiguration problem arises. As a result, the study of virtual cell dynamic scheduling problem with rush order arrival can be divided into two parts. The first part is the virtual cell reconfiguration problem when the existing virtual cells cannot meet the production requirements of rush orders, and the second part is the virtual cell dynamic scheduling problem with rush orders insertion.In order to solve the problem about virtual cell reconfiguration, the article proposes a new two-stage virtual cell formation method by mathematical programming and complex network theory in graph theory, which considers multi-process routes, production lot size,processing time, due date and production capacity of the machine and some other factors. In the first stage, in order to determine the routes of parts and manufacturing resources required, the article creates a virtual cell resource selection model based on mathematical programming theory, which can be solved by Lingo11. The goal of the model is to minimize the total processing cost. The second stage is about the clustering analysis of manufacturing resources, which simultaneously considers part-based clustering and process-based clustering and constructs two network graphs based on parts and processes respectively. And the implementation of virtual cell reconfiguration benefits from a partitioning method for community structure in weighted networks based on node similarity.In order to solve the problem about virtual cell dynamic scheduling with rush ordersinsertion, the article studies the resource conflict problem caused by the random disturbance and considers the cogeneration and characteristics of shared resources in production process of virtual cell based on time constraints network and graph theory. Taking into account the machine resource constraints and delivery time constraints, the article creates a time constraint network model about dynamic scheduling in virtual cell, which is solved by collaborative optimization algorithm between cells based on two-layer time constraint network and human-machine cooperation & reaction algorithm based on degree.At last, in order to verify the value of the proposed method in actual business, the article applies the method of virtual cell reconfiguration and dynamic scheduling to the pipe manufacturing processing based on the detailed analysis of the production management situation and the existing problems of pipes processing plant in HDZH. The results show that the proposed research program has high feasibility and effectiveness.