Applying design for assembly to redesign a crew door

Design for assembly (DFA) is an integrated product development tool used during product design to reduce assembly time and manufacturing time, thereby reducing product cost and increasing product quality. DFA is a relatively new technology that is used in design and manufacturing. It is an important part of what makes a company a world class competitor today.;The door was designed using Unigraphics II, release 10.5. This thesis discusses some modeling techniques that were used during the design. With computer aided design (CAD), it was possible to design and manufacture very accurate parts and assemblies, eliminate the mismatching and interference problems that happen very often during conventional design, and dramatically reduce engineering changes and reworks. The solid modeling and assembly modeling also eliminate the expensive engineering mockups, thus reducing the cost.;This thesis presents DFA technology, using the concept to redesign a transportation aircraft crew entry door. By comparing the main structure of the new design with the existing door design, it can be seen that applying DFA to the design eliminated 46 percent of the parts count and 40 percent of the fasteners. It also simplified the structure and reduced the number of manufacturing operations and the assembly time. This reduced the door cost substantially, and at the same time improved producibility, reliability, and maintainability.