IMPROVEMENT DAYS OF INVENTORY HEAVY EQUIPMENT PARTS IN PT. UNITED TRACTORS SITE SUMBAWA THROUGH DEMAND FORECASTING & INVENTORY MANAGEMENT

Abstract

In the context of a request for spare parts, PT. UT Sumbawa is expected to provide optimal levels of service or spare parts availability to customers. The main challenge in this research is fluctuations in demand for spare parts which result in service level performance not reaching the target of 80%. The high inventory of spare parts causes Days of Inventory (DOI) performance to not be achieved. The research aims to find the most effective spare parts inventory management method to reduce DOI. Problem analysis using the 5 Whys method. Comparison between moving average forecasting methods from several time series and Economic Order Quantity (EOQ) used to control inventory in the hope of identifying the best method to achieve research objectives. The Swiss Cheese Model method is used to analyze the causes of error in the ordering process by employees, as well as the role of the organization in service performance, with the aim of providing prevention recommendations. Task Analysis is also used to analyze spare parts supply flows to increase spare parts lead times to customers. The research results show that the moving average method with a time series of 12 months and EOQ can increase stock effectiveness and efficiency, resulting in a decrease in DOI. The Swiss Cheese Model method is also effective in identifying the causes of error process order and its overall organizational impact. The VHS system was proposed as a solution to improve service level measurement and speed up the supply of spare parts to customers.