Assembly-line methods

This thesis presents a methodology of Comparative Analysis of different Design for Assembly (DFA) Methods. Three DFA methods, Boothroyd's Design for Assembly, Design for Assembly Guidelines and Value Analysis are compared. A "Select DFA Software," is developed using Turbo C++, which would enable a product designer to make a comparative analysis of different DFA methods from which the designer can chose from. In using the Software the designer is not required to know in detail the different DFA methods. Responses to, easy to understand factors that affect the selection of a DFA method enables the designer to use the Software meaningfully. Two case studies are conducted for application of the DFA Software and the three different DFA methods.

Current ankle implant designs have shown significant improvements in last ten years. However, failure rates are still high and about 30% of patients ended up with fusion joint or lower leg amputation after ten years of first operations because of long term associated pain. A new ankle joint implant presenting in this study (Vo-ankle implant) was designed to base on the Design for Assembly (DFA) principles to optimize the device biomechanically. It overcomes most of problems shown in current ankle implants. The new ankle implant has four major advantages over the current models. First, the new ankle constructed to distribute loads evenly on the joint implant with variable axes of motion. Second, the implantation requires much less bone resection. Third, the new ankle design has a simpler and easier technique to implant. Lastly, the new ankle design employs one joint intact operation same as that of a true ankle joint.