Abstract: A development support system for supporting new product development activities including designing, manufacturing experimental models and testing the functions of the experimental models and for providing an environment for the cooperative activities of a plurality of members of a development project team has a model storage for storing product models, resource models of resources to be used for product development and product development activity models; a target storage for storing target values of schedules of product development, and the cost and the performance of the product; an estimating unit for estimating schedules of product development and the cost and the performance of the product on the basis of the models stored in the model storage; a support unit for support the operations of the members of the development project team for making reference to the models, the target values and the estimated values, and changing and particularizing the models, the target values and the estimated values; a noti