Product cost is one of the most important factors affecting product market share. Traditionally, product costs are estimated after they are manufactured. However, in this way, the best opportunity to control product cost is lost. In this paper, a method trying to reduce product cost at the design stage is proposed. This method is called Design to Cost (DTC). According to this method, product structure can be optimized with the application of value engineering and Design for Manufacturing/Assembly (DFMA) criteria in the conceptual stage of product design. During embodiment design, products are evaluated economically on the basis of the product model which includes manufacturing, assembly and test cost information. According to the results, products are redesigned before manufacture, and the production cost is reduced. Product costs is one of the most important factors affecting product market share. Traditionally, product costs are estimated after they are manufactured. However, in this way, the best opportunity to control product cost is lost. In this paper, a method trying to reduce product cost at the design stage is proposed. This method is called Design to Cost (DTC). According to this method, product structure can be optimized with the application of value engineering and Design for Manufacturing / Assembly (DFMA) criteria in the conceptual stage of product design. Products that are economically on the basis of the product model which include manufacturing, assembly and test cost information. According to the results, products are redesigned before manufacture, and the production cost is reduced.