Multi-line Workshop Layout Optimization Based On Improved Genetic Algorithm

Plant Layout Problem(PLP) is one of the important parts in manufacturingprocesses, a good shop layout not only can help to improve production efficiency,accelerate the production process, but also can influence the production costs byeffecting on the costs of materical handing so as to improve the economic efficiency andthe market competitiveness of the company. Beacause of plant layout is a typicallyNP-hard problem, so that traditional optimization algorithms is difficult to get theoptimal solution, so this paper adopted the most widely used genetic algorithm assolution methd, and traditional genetic algorithm has be improved.As for in the study of multiple lines workshop layout, the definition of the distancein the traditional optimization process is not reasonable, it takes the sum of absolutevalue of the X and Y Resolution values of the two points, without taking into accountthat when two equiments are in different span there will be a transport barrier. Therefore,the rail on the ground may also be used, as a aresult, there will be two kinds oftransportation costs. Based on the analysis of their disadvantages above, so this paperpresented a new improved mathematical model of appropriate definition andconsidering the position of the rail on the ground. The objective function not onlyconsider the costs of logistics transportation but also taking the cost ofnon-manufacturing process logistics transportation into consideration. It made the PLPmodel more closely to actual production.As for sometimes in different workshop the rail on the ground is placed in differentposition. In this paper two different mathematical model were developed for the studyof rail seated in a fixed position or not two different cases. Therefore, the optimization ismore suitable to actual circumstances.In this paper, we established an optimization model of multi-objective PLP, basedon the single objective optimization with the costs of logistics transportation, theutilization rate of the plant as objective function. And the solution procedure is given.In the process of genetic algorithm solution, we coded the position of rail on theground, the alignment of equipment and the clear span simultaneity. Besides, the crossing and variation operation were improved. Different kinds of crossing andvariation project were persented. It made the optimization added up to more practicalsignificance.Besides, we took the reatrictions on the specific large-scate equipments intoconsideration and gave the solution procedure about specific plant layout withlarge-scate equiments.On the basis of the theoretical study, we compiled optimization program ofworkshop layout by VC++. And the optimization examples show the effcctiveness ofthe algorithm.