This paper discusses target cost management (TCM) from the viewpoint of simultaneous engineering. Firstly, it shows empirically how simultaneous engineering is implemented in Japanese companies. Secondly, it formulates and then tests hypotheses on the influential power of managers involved in the process of target costing. Thirdly, it describes processes of interactive control directed at information and value sharing among managers that help explain why simultaneous engineering is working effectively in Japanese companies. It also formulates and tests hypotheses on information and value sharing among managers. Fourthly, it concludes that interactive control in TCM helps generate unique ideas for product development and cost reduction, and that Target Cost Management is a key subsystem of strategic cost management.