Designing of Raw Material Scheduling Supply Multi on Supplier Strategies with Price, Lead time, and Stochastic Demand Variations. Case Study: Electricity Manufacturer

Raw Materials are one of the important things in manufacture. The availability of these items is very important for the production process to take place. The researcher will research an electricity company. The electricity company produces electricity equipment. The four types of electricity equipment are cartridges, thermocouples, tubular and mica heaters. Some of them have stochastic demand. Each of them has three components of the same raw material and used to make the product. However, the company cannot fulfil the demand because raw materials are not available, so consumers are looking for items elsewhere. This delay occurred because of the delay in sending raw materials, so the company has to wait until the ordered items arrive. This problem is being more complicated by the differences in parameters for each supplier such as price differences and lead time of arrival. Therefore, the company must determine the optimum scheduling and safety time by minimizing inventory costs as a result of Mixed Integer Linear Programming (MILP) being used in resolving these problems.