To design, operate and manage the optimum chemical process, we needed to master many important technical components; such as computer aided technology, conceptual design, design of control, equipment design, business optimization, etc. Each component consists of huge amount of knowledge. Expertise for each components are needed to master the necessary skill and to successfully implement them. Among all the disciplines in chemical engineering and other related subjects, it is very difficult to identify the key components. Moreover, it is even more difficult to bring all the specialists together and integrate all of their technologies. To achieve this integration, "technology fusion" serious planning and management are required. In Mitsubishi Chemical Corporation, we have carefully laid out the necessary components for achieving the optimum chemical process. Furthermore, we have laid out the foundation and the necessary procedure for us to reach our goal, "the 21st Century’s Plant."