Design for Trustworthy Software: Tools, Techniques, and Methodology of Developing Robust Software

TRIZ, QFD, and Taguchi Methods are indeed three separate quality-enhancing technologies, but they often are logically related by a Venn diagram, as shown in Figure 12.2. The basic idea here, one commonly stated in the TRIZ literature, is

QFD + TRIZ + Taguchi Methods = customer-driven robust innovation

Figure 12.3 shows the relationship of these tools. A filled-in circle shows that a column has a significant impact on a row. Lightly filled-in circles indicate a moderate impact, and empty circles indicate a weak impact.

QFD, TRIZ, and Taguchi Methods are all clearly very much upstream methods, but the order of their application in a robust design process seems to be QFD, and then TRIZ, and then Taguchi. QFD systematically translates the customer's needs and desires into the engineer's language. Product qualities important to the customer are linked to the design's engineering requirements and target values. TRIZ then provides a methodology to develop a creative solution, and Taguchi Methods determine the design's parameter values. Each of the three tool sets has its particular focus in the design stage of a product or process, but together they form a complete and balanced methodology to support robust design. John Terninko presents a workshop with several case studies for hardware engineering and manufacturing, illustrating the synergy between these three interlinked methodologies.^[10]