Research On Scheduling Of Dyeing & Printing Plants And Design Of The Associated Scheduling Software

Dyeing & Printing industry is a typical chemical batch process, also an important component of the manufacturing industry of China, but most of dyeing & printing enterprises still rely on artificial arrangements of dye-vat production. Therefore, a rational production scheduling by the computer technology can significantly improve the situation of dyeing & printing enterprises, increase the production efficiency and reduce their production costs.In this paper, based on the production characteristics in dyeing & printing industry, such as large amount of product kinds, flexible production equipments, having customer-attribute and complex switching costs, an optimal scheduling proposition is proposed. According to the process of dye, the core process in dyeing & printing production, the associated mixed integer linear programming (MILP) problem model is established by directly handling the scheduling order of dye-vats as the decision variables for the optimization objective function. This model fully considers the actual situation of the production in dye process, such as multi-production lines, multi-product, multi-related orders and switching costs related sequence and equipment.Dyeing & printing enterprises have a particularly high demand on the speed of scheduling algorithm because enterprises need frequently rearrange their productions. In view of this demand, based on GA (Genetic Algorithm) and PSO (Particle Swarm Optimization), a special coding method for dyeing & printing scheduling is introduced, moreover, rules for initial population in GA is introduced. As a sequence, an improved genetic algorithm is designed. To speed up the algorithm, the way of evolution in GA is reformed by using the thought of PSO, as a result, a new evolution algorithm is designed, which has tremendous effectiveness on solving large-scale optimization problem and speeding up the solving process. Simulation results illustrate and confirm the method. Moreover, some heuristic rules are introduced to improve the algorithms.Finally, a scheduling software for dyeing & printing production is designed. Based on the previous theoretical research, considering the actual demand of printing and dyeing enterprises, meanwhile taking account of the accuracy, reliability, security, interactivity, ease of use and versatility of the system, a complete set of dyeing & printing scheduling software is developed.