The impact of product design on manufacturing cost is significant. A product that is difficult to assemble will increase its production cost. An accurate process for identifying problematic parts before they are released for manufacturing is needed. In this paper, we will present a method for generating structured product coding system (SPCS) product assembly tree. The SPCS is part of an integrated design-to-manufacturing system for analyzing and calculating products' manufacturing cost in a virtual environment. It models assembly and disassembly operations of both parts and tools used in manufacturing a product. By using the system, a product designer is able to estimate the impact of every part used for building a product before production.