The present research work carries out a study to improve supply process of auto-parts in Autoservicios Untiveros SAC’s Auto Repair Centre based on Industrial Engineer’s techniques like reorder point, business process reengineering and simulation process to improve problems related stock shortage. It was also proposed alliance between American company called Mighty to supply auto-parts to preventive maintenance. The issue mainly is no count with suitable purchase process for auto parts to preventive maintenance, it causes break of stock it reduces effectiveness and efficiency level. The research techniques were observation (visits to Autoservicios Untiveros, historical data recollection), and general manager interview. The results have been modeling from current scene that does not count with safety stock policy. With Arena software a simulation in stable state was carried out with si...