Though this quality tool will be discussed in detail in Chapter 7, a quick review is given in this chapter in order to round out the quality tools integration with the six sigma principles. Much like QFD, design of experiments (DoE) can be used in both design and manufacturing, and hence can influence both parts of the six sigma equation: design specifications and manufacturing variability.
DoE can be used in order to focus the new product development project not only on cost, as in DFM, but on several other areas such as quality, variability reduction, and specification selection. The same set of experiments can be used to optimize any of the parameters mentioned above: product cost, quality, or specifications. DoE has been widely used in manufacturing, but not in design, much like six sigma. It is the intent of the author to demonstrate the successful use of DoE in design as well as manufacturing, especially in case studies where it was used to enhance the attainment of the six sigma goals.