PT. XYZ is a service company in the field of marine expeditionary, precisely on shipping or ferry ship with a line on track Merak - Bakauheuni. In the registration of spare parts, this process is still manual, and reparations of broken or damaged spare parts are still using the official report form. This study analyses the process of recording parts running at the Munic Line. Then the analysis will be done to provide safety stock inventory and Reorder points based on the lowest total cost, which will also be supported by the inventory system design. The method used to analyze the model inventory analysis is the EOQ model, EOI, and Min-Max Inventory. The system's design will use the concept of Unified Modeling Language (UML) and the concept of Object-Oriented Analysis and Design (OOAD) and design analysis based on the model Satzinger with Unified Process Life Cycle stages. It is intended to support the process of recording and registering spare parts inventory in the future