Abstract: Production logistics would affect output rate directly,for the main question of not to delivery in time in a company of main produce car,to finding the main key link is very important.It was found by observation and analysis that was the painting process in affecting the yield of automobile.Painting production logistics included five stations that pre-treatment,coating,inspection,drying and scratch,according to the current job situation of each station,the application of Witness software in modeling and simulation,the running result revealed that the coating station was the bottleneck because of the station was only one line and sometimes needed to spray a variety of colors,two spray coating lines were added to solve the problem which waiting too long and moving back and forth,a new model used Witness was established and the result showed the production line running blocking has been obviously improved,the average time of painting processes reduced from 100 to 88.5 minutes.The improvement scheme applied in the enterprise,the car’s the monthly output increased from 1 000 to 1 250 units,for the enterprise created a good economic benefit.

Key words: production logistics, coating, simulation, optimization