Although domestic casting related industries occupy an important position in the production of products using new materials, they are having difficulties in management due to intensified competition in the same industry and China s overseas market erosion. In addition, due to the high level of labor intensity, there is a shortage of skilled manpower for precision casting and the burden of new investment is high due to financial difficulties. Considering the reality of SMEs, in order to overcome management difficulties, it is necessary to improve bottleneck processes to minimize investment and maximize profits.\nIn this study, we propose a method to improve the efficiency of work by repositioning the equipment to fit the work environment or by laying the manpower in the proper place while maintaining the existing equipment and resources based on the case of the mold maker company W.\nWe conducted brainstorming to identify the current status of the company and draw out problems, and conducted ARENA simulation to analyze and improve the status of the current process. As a result of the simulation, we have found the erroneous process, reallocated the equipment to solve the bottleneck, and improved the work environment to improve the worker safety. This has resulted in a 150% increase in productivity and less work s fatigue.