IPTEK Journal of Proceedings Series No. (1) (2020), ISSN (2354-6026) The 1 st International Conference on Business and Engineering Management (IConBEM) February 1 st 2020, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia 432 Abstract—PT. Mortars is an instant cement producer with many product variants. Some problems that PT. Mortars encountered are uncertainty of demand, limitation on production capacity, and inventory capacity, which caused product shortages and high inventory costs. The production scheduling process is produced manually so it requires a long time, relying on the ability and experience of the production planner which is vulnerable to mistakes. Therefore, new methods and tools are needed for inventory control and production scheduling to make sure goods are delivered to customer just in time while maintaining operational efficiency. Periodic review system (R,S) and (R, s, S) methods are proposed in this study to improve inventory parameters and reorder systems that have an impact on service levels and inventory costs. The tools are designed using Microsoft Excel software with solver add-ins functions and linear programming approaches to generate optimal production schedule decisions automatically. In order to determine the level of service and inventory costs generated by each method, a simulation is conducted by using the tools that have been made. The simulation of the existing method produces a service level of 98,64% and a total inventory cost of Rp. 1.167.160.494. The periodic review system (R, S) method resulted in increasing service level of 0,96% and lower inventory cost of Rp. 15.130.801 while the periodic review system (R, s, S) method resulted in increasing service level of 1,29% and a lower inventory cost of Rp. 448.653 compared to the existing method. The periodic review system (R, S) method produces the lowest inventory costs while the method (R, s, S) produces the highest service level compared to other methods. Keywords—Production Planning and Inventory Control, Periodic Review System (R, S), (R, s, S), Linear Programming. I. INTRODUCTION N the globalization era, companies that have reliable supply chain management will survive and win business competition. Although companies can produce good quality products at low prices, but the availability of products on the market is not guaranteed, then the customer will switch to competitor products or substitute products [1]. Uncertainty of demand is one of the problem faced by the company in meeting customer demands. To solve this problem, efficiency along the supply chain path is needed. So it takes inventory control planning and production scheduling in order to minimize production costs and improve service levels [2]. Good inventory management is needed to reduce the risk of demand uncertainty. In businesses that use make-to-stock operating system, efficient inventory management is very important. This is because the inventory along the supply chain path has major implications for company's financial performance [3]. The amount of inventory is usually very large, even the value exceeds 25% of the total value of assets held. To keep the inventory level at the desired amount, it needs to balance the supply and demand. Mathematical models programming plays a very important role in the scenario of inventory control strategies and production scheduling, [4]. With optimal inventory control and production scheduling, product availability and operational efficiency can be achieved in accordance with existing The Establishment of Decision Making Support Tool for Inventory Control and Production Planning with Periodic Review System and Linear Programming Approach Redy Ardiansyah *1 , I Nyoman Pujawan 2 , and Niniet Indah Arvitrida 2 1 Department of Management Technology, Institut Teknologi Sepuluh Nopember, Indonesia 2 Department of Industrial Engineering, Institut Teknologi Sepuluh Nopember, Indonesia e-mail: redy.mmt17@icloud.com I Table 1. Inventory Days of Supply Parameters Products Demand average Inventory days Order Up to level Units bag/ day Days Bag Total 15.260 61.344 MR-200-20KG 568 6 3.408 MR-200-40KG 601 6 3.606 MR-202-40KG 462 6 2.772 MR-250-40KG 762 6 4.572 MR-270-25KG 98 15 1.470 MR-272-40KG 231 6 1.386 MR-290-40KG 118 8 944 MR-100-40KG 251 5 1.255 MR-101-40KG 14 6 84 MR-301-40KG 1.161 2 2.322 MR-302-50KG 4.614 3 13.842 MR-380-40KG 2.227 3 6.681 MR-382-40KG 727 3 2.181 MR-400-25KG 1.395 3 4.185 MR-402-40KG 258 5 1.290 MR-410-25KG 10 30 300 MR-420-25KG 411 4 1.644 MR-422-40KG 51 6 306 MR-440-40KG 26 15 390 MR-440-50KG 443 4 1.772 MR-443-40KG 93 2 186 MR-445-40KG 29 15 435 MR-450-40KG 316 4 1.264 MR-460W-25KG 69 15 1.035 MR-480-25KG 148 6 888 MR-485-25KG 48 4 192 MR-700-25KG 27 30 810 MR-800-20KG 50 30 1.500 MR-830-40KG 46 12 552 MR-840-25KG 6 12 72