Lean Improvement Of EMU Maintenance In Workshop A Based On Value Stream Analysis

China’s high-speed railway has developed rapidly in recent years,leading the world in terms of technology and equipment,total operating mileage,manufacturing and maintenance capacity.However,with the continuous expansion of the using scale of EMU,EMU maintenance companies are facing multiple challenges.On the one hand,the company system reform of the railway administration is deepening,and the competition of EMU maintenance market is becoming more and more fierce.On the other hand,the types of EMU are increasing gradually,so the difficulty of maintenance is increasing.Faced with the transformation demands of EMU maintenance companies,Lean Production Theory can help them to establish a management system suitable for themselves and improve production efficiency.This thesis studies and summarizes the lean improvement of the T section in workshop A of EMU maintenance base.First of all,it is essential to trace the source of Lean Production Theory,understand lean methods and tools,and make sufficient preparations for improvement in talent training,cultural cultivation,organizational structure and other aspects.Secondly,it undergoes an in-depth field investigation,identifying and analyzing maintenance problems in workshop A of EMU bogies with the use of value flow mapping.It is found that workshop A has unreasonable site layout,large inventory of products,low efficiency of spare parts inventory management,delays in delivery and other problems,and it identifies the bottleneck process.Then,discussing repeatedly combined with the EMU maintenance characteristics,draw ideal value flow mapping in the future.Based on the value flow mapping,it designs workshop A lean production improvement plan,including the use of pull production method,the balance of the production line,the adjustment of the site layout,the building of a safety inventory model,the development of intelligent assembly system.According to the plan,the pilot is selected for trial operation,constantly revising it according to the trial operation,then summarizing the implementation experience of the plan.After the success of the pilot,the whole workshop is improved step by step.Finally,through a series of improvements,workshop A helps to guarantee the operation of improvement plan in the four aspects: organization,culture,system,equipment.At the same time,the amount of maintenance times increased by 15.6%,the maintenance cycle is shortened by 16.9%,the production site is clean,and the enthusiasm of employees to participate increased.In addition,inventory and production waste is reduced.