As current product design processes tend to be distributed across numerous technical fields, it has become increasingly difficult for the detailed design arising in each field to preserve the early overall design concepts that ideally should be incorporated in the final product. This paper proposes a collaborative decision method that achieves these kinds of product development targets. First, complicated relationships between product criteria and design variables are approximated with quadratic polynomials using the Response Surface Method. Influences of design variables with respect to criteria are calculated from the equation results, and are applied to estimates provided by enterprise sections such as design units, research teams, and so on, to achieve a clear and detailed picture of potential product performance. Based on these estimated relationships, all sections can offer more effective design alternatives and predict the product performance. Moreover this method can also predict and evaluate the development costs required to achieve a range of development goals.