This paper is motivated by a case study performed at a company that manufactures two main types of customized products. In an effort to significantly increase their throughput capability, the company created a new production scheme based on takt time calculations. To achieve a smooth flow of production, they desired low Work In Process (WIP) inventory in order to make all components move simultaneously. However, the order of operations in key shared resources implies that a simple takt time calculation cannot provide enough information in determining achievable throughput. The process includes several parallel assembly lines that “converge” to common resources. In certain cases, these components are joined into one unit; in other cases the components split again for further customization. We attempt to improve throughput using a combination of takt time and simulation by understanding how each stage of the system interacts with other stages.