The case company is a traditional automobile parts maker and one of leading domestic suppliers in the field of instrument panel design and manufacturing. However, the performance of corporate operational management, such as gross profit, inventory control, and the cost of manufacturing and development of products are still far away from reaching goals. Dr. Goldratt believes that we are facing more severe competition in the global market, not only continually carry out to upgrade our new technology but also need to establish unique Decisive Competition Edge (DCE) for sustaining management tools of enterprise. This study utilized Dr. Goldratt’s Strategy of Tactical Tree (S&T Tree) to establish DCE for the case company. The roadmap has been carrying out by interviewing different level of managers and acquires information for analysis and verification and to receive consensus and commitment from management levels. Consequently, completion of the S&T Tree can be guiding principles for future corporate development goals and action plan.