PT. PINDAD (Persero) is Indonesian manufacturing company in defence and industrial equipments that fulfil the needs both for military and commercially. One division of their business unit is machine division industry and services that produces ocean steamer components. Component to be investigated in this research is steering gear (tool steering in a sea ship). Inventory is the asset that very expensive in an enterprise, usually about 40% of the total investment. Manufacturing companies can run their operationally well when their inventory of raw materials could be met just in time, hence management in handling raw material is very important. Material Requirement Planning system is a method to determine the needs of raw materials in each production phases. This research is using Lot for Lot and Economic Order Quantity method. Lot for Lot method provides raw material supplies based on the needs of production in minimum quantity and Economic Order Quantity method provides raw material supplies based on minimum order quantity.
Based on comparative inventory cost analysis of Steering Gear that manufacture by PT. PINDAD (Persero) in 2012 using ABC classification, the analysis conduct in A class because controlling raw materials of this class should be more strict than other class. The purpose of this research is to find out the total cost of Steering Gear inventory by using Lot for Lot and Economic Order Quantity method and to determine which method that produces minimum cost of Steering Gear inventory.
The variables that examined are bill of materials, master production schedule and inventory. In this study, the data processing is carried out with the help of Microsoft Office Excel 2007 to simplify and minimize error in calculation. The results of calculation by using Lot for Lot method for POWERPACK is Rp 51.300.000, ELECTRIC CONTROL PANEL is Rp 46.875.240, ROD EYE MOUNTING B125R70 is Rp 8.119.440 and HYD CYL.B125R70S493 is Rp 9.450.000. The results of calculation by using Economic Order Quantity method for POWERPACK is Rp 73.880.769, ELECTRIC CONTROL PANEL is Rp 67.508.358, ROD EYE B125R70 MOUNTING is Rp 15.034.347 and HYD CYL.B125R70S493 is Rp 19.250.000.
Implementation Lot for Lot method is better compared to Economic Order Quantity method in control the inventory of Steering Gear in PT. PINDAD (Persero) since the method can minimize the cost. Ordering system which applied in company should be according to stock in warehouse and also by the schedule of production so that the cost of inventories not too high and the availability of the inventories also not delayed. The integrated system that applied between Departments can simplify checking the inventories, supervising production process and controlling by the authorization.
Keywords: Inventory, Inventory Control, Material Requirement Planning, Economic Order Quantity Method.