The aim of this research is to introduce the reader to a new perspective on the framework for designing a manufacturing line project in Japanese automobile manufacturing plants. All manufacturing aspects, manual, automated and hybrid manufacturing lines are considered; however, which line should be used for the factory is always under investigation within the factory. Simulation studies that include resource utilization, line productivity and manufacturing costs help to identify the most suitable manufacturing line type within a factory. By utilizing simulation studies, designers can make reliable decisions upon suitable manufacturing lines faster than conventional methods based upon engineering experience. In order to understand the framework of manufacturing line design, a project to design a new automobile component manufacturing line was investigated in this study, and the chosen manufacturing line was also checked by the manufacturing activities in the factory.