With respect to the characteristics of product structure in large discrete manufacturing enterprise, a multiple level product structure which integrated self-made items, outsourcing parts, raw materials and making processes was proposed. Afterwards, aiming at the optimization and control for product design cost, a product and／or tree structure based on configuration model was established, in which the assembly feasibility satisfying the requirements of an item making process was represented by the definition of correlation between its components. Based on the single level product and／or tree structure, a design cost optimization model was then given. Simulation experiments were employed to demonstrate its effectiveness. The experiments showed that the proposed Opt-BOMP on model DFC can achieve a better cost product design than the DTC model. The Opt-BOMP has considered the quality requirements of a product, the impact of supplier on outsourcing materials, the technology requirements of a product and the combination of product design and manufacturing, it can improve the feasibility of a product design.