Simulation Model Design and Improvement of Raw Material ware house layout with class-based storage method: A case study

This paper presents a simulation model design and improvement of raw material warehouse layout with class-based storage method at a company, namely PT XYZ. The identified problem lies in the raw material warehouse, namely the placement of raw materials is not in accordance with the type of class of raw materials and has not implemented the FIFO system. The total time for moving raw materials is 100.79 minutes which exceeds the time that the company has prepared for moving by 60 minutes. This study aims to design simulation model and make improvements to the raw material ware house layout of the company by using Class Based Storage method and ProModel software. Identify problems using a check sheet by looking at the actual state of the raw material warehouse. The initial simulation was made by looking at the average observation data of incoming raw materials per month and the cycle time of 30 days. There are 15 types of raw materials stored in the raw material ware house with 3 different storage areas. The initial raw material ware house layout simulation results with a total of 246 pallets get a time of 91.14 minutes. Furthermore, calculations are carried out using the Class Based Storage method and then forming classes according to the frequency of the moves, namely Area 1 with a total moving frequency of 68.21% which is placed close to the In/Out Area and Area 2 with a total moving frequency of 31.79%. After that, 2 improvement scenarios were made, the first scenario, namely layout improvements using the Class-Based Storage method, obtained transfer time of 85.17 minutes. The second scenario is the layout improvement and the addition of 1 forklift and the displacement time is 43.19 minutes. Based on the selection of proposed improvements using the Bonferroni Test, the best proposal was obtained, namely the second proposal with a reduction percentage of 52.6%.