To be competitive, companies must constantly innovate, and having efficient and well-managed supply chains is undoubtedly an important success factor. In the case of spare parts manufacturing, supply chain management is a very complex and arduous task. Quite often, spare parts have to be produced for products that have been on the market for very long, with the need to keep a large and varied stocks to ensure supply service level. With an increasing investment in the development and applications, the Additive Manufacturing (AM) technology can yield significant benefits to spare parts manufacturing. AM allows the production of parts with a high level of customization, without the need for setups, and helps to decrease costs, inventory levels and lead time. This new reality creates numerous challenges, forcing the design reformulation of traditional supply chains, and leading to an allocation of the production of certain types of parts downstream. This paper proposes a simulation model to address the use of the 3D printing technology on the supply chain of an elevator maintenance service provider. The simulation model allows the assessment of new supply chain designs, measuring their performance, thus avoiding the need of experimenting new solutions in the real system.