A pharmacy typically store pharmaceutical products in warehouses before being sold to the customer. Stacking of products in the warehouse can reduce the efficiency of the warehouse and increase the costs associated with inventory, which raised the problem of how to predict the stock of each product to the right in order to avoid excess/shortages. Therefore, this study aims to develop a decision support system for inventory management in pharmacy, especially to predict next inventory using FAHP and SPA approach, so the prospect of inventory management will be more optimal. The study also proposes a model to predict inventory. These results indicate that the inventory prediction accuracy using this model approach more accurate 18% than the inventory prediction accuracy by a pharmacy inventory manager, so this approach can be referred to as a decision support system.