The aim of this study is to define Design For Assembly (DFA) technique in the light of concurrent engineering methodology, determine the principles and manifest these principle effects on an application through comparison. There is a re-design process in glass block holder and blocks of an automation machine which is used in glass production industry. The 3D models of the original and new design have been made by using Solid Works 2006. The new design is made in the light of DFA and with paying attention to the Boothroyd & Dewhurst method. The re-designed mold is applied to large volume production process and healthy results were obtained. At the end of this part, the tables which are derived from the old and new data are prepared and their comparison is made.