Research On Multi-Objective Scheduling Of Workshop Considering Significant Differences In Equipment Utilization Rate

In recent years,with the development of high-tech,huge changes have taken place in Chinese manufacturing market,which has brought new opportunities and challenges to many manufacturing industries.In order to meet the variability and diversity of customer needs and enhance the competitiveness of enterprises in the fierce market environment,many manufacturing companies have turned to flexible production.Changes in production methods will affect the production workshop scheduling methods that are closely related to it.The scheduling method has a strong correlation with the efficiency of the enterprise.Therefore,compared with competitors of the same production level,having a set of scientific and effective,high flexibility,and full use of existing resources to achieve the best performance of the entire production system scheduling plan is the key to enterprise competition.Manufacturing companies are gradually investing more energy in the scheduling of production workshops to ensure that the company has a strong competitive edge in this complex and changing market environment.This article takes the gear production workshop of company B as the research object.After on-site investigations,it was first discovered that the company’s production workshop scheduling plan formulation method and formulation content are relatively inadequate.The planner only manually prepared the weekly production scheduling plan,and did not fully incorporate the company’s wide range of products and various equipment into the scheduling plan design.There is a significant difference in the utilization rate of production equipment directly,which indirectly weakens the company’s grasp and control of each situation in the production process.Once an error occurs in a certain link,it will increase the burden on employees,and production will be blocked,which will directly affect the production efficiency of the enterprise.Secondly,it was found that the workpiece was processed in the production process,and it was not determined on which machine the next process was produced.The randomness of the machine selection caused a waste of the transportation cost of the workpiece.Transportation costs are related to the company’s production costs,which affect the company’s revenue and profit.In response to these two problems,this paper constructs a multi-objective workshop scheduling optimization model that considers the significant differences in equipment utilization.On the one hand,the objective function of the model builds the objective function of total production cost from the perspective of the enterprise.The total production cost is composed of the processing cost of the workpiece and the transportation cost of the workpiece between the processes,and minimizes it.On the other hand,from the customer’s perspective,the absolute value of the order’s maximum lead/due date is the objective function,and this function is minimized.Enterprises try to avoid early or late delivery,so that the product completion time coincides with the delivery time,and improves customer satisfaction.Then,the MATLAB programming software is used to realize the NSGA-II algorithm design.Combining the actual production data of company B,a case study is conducted to compare the indicator data before and after improvement.Since the optimal solution set obtained after optimization is Pareto,this paper selects the maximum value of the optimization results and compares it with the result of the current scheme.The results show that the optimization scheme designed in this paper can save 2467 yuan in workpiece processing and transportation costs,and the maximum completion time of the entire production system is shortened by 34.42 hours.The absolute difference between product completion time and delivery time is reduced by 13.6 hours,and the average utilization efficiency of all machines is increased by 5.7%.Finally,considering the fluctuation of company B’s demand,this paper selects representative products through the ABC classification method to test the suitability of the model.The test results show that the model is applicable.It can provide learning and reference ideas for multi-variety small batch manufacturing enterprises in the period of enterprise transformation and upgrading and immature production scheduling.