Inventory Level Optimization of Raw Materials for Ready-Made Garment Industry XYZ Pty Ltd using Mamdani Method of Fuzzy Interference System

Abstract

Every company who performs production activities needs inventory of raw materials. The most important thing which is mandatory for all companies when performing their production activities is management of inventory, as inventory is an asset for a company. Availability of raw materials in the industry is expected to facilitate production/service activities to meet consumer needs. Ready-made garment industry, XYZ Pty Ltd is a family business established in 2004 located in Jakarta which engages in textile manufacture and has shown a relatively high demand. While XYZ Pty Ltd attempted to meet the demand, the inventory level was not able to balance with it, resulting in after-hour work of employees. In order to provide appropriate solutions, we proposed some strategies using Mamdani method and TFN (Triangular Fuzzy Number) range which selected appropriate rules to optimize inventory level of the company. Average of range score Fuzzy Interference System obtained for both production level and demand level were 36,500, while average of range score Fuzzy Interference System obtained for Inventory Cost and Inventory Level were 2,250,000,000 and 13,900, respectively. Rules resulting in a high inventory level are very good for use either together with other levels or not. Rules resulting in an intermediate inventory level are also good for use, in particular together with low and intermediate demand levels. Rules resulting in a high demand level are still good for use. On the other hand, rules resulting in a low inventory level are not good for use.