5.1 Introduction

Six-sigma is basically a goal of process quality. However, it must always be remembered that a quality process is just one of the key elements of product reliability. Designing for reliability encompasses a great deal more than this. If the individual parts themselves do not start with an adequate level of quality, and if the need for reliable design is not adequately addressed during the development, final product reliability at the six-sigma level is simply not possible. Design for six-sigma is a business process focused on improving profitability when properly applied. It generates the right product or Service at the right time at the right cost.

One of the important tasks of the design process is to translate the overall functional requirements for a new system into its physical requirements in relation to the performance, power consumption and cost. In this book we have discussed six sigma and reliability. Reliability ensures failure free design and Six Sigma ensures defect free process. Implementation of six-sigma program requires close co-operation between the product design effort and the design of the manufacturing process. One of the goals of product design is to minimize the variations in the process to ensure the production of the desired characteristics and to center the process on the target nominal value of the desired parameter.

There are several analysis tools for building reliability and ensuring a six sigma process in the design. The main design...