In most cases, the number of customers may be too many having different expectations, some of which may be contradictory to those of other customers. For example, some customers expect high mileage from an automobile, while others want more power. Another set of customers may want both mileage and power. The designer of the engine of the automobile has to satisfy the expectations of this whole group of customers in the best possible way. Customers have their own unique way of expressing their expectations, when enquired about. QFD helps to convert these expectations, called 'Voice Of Customers' (VOC), into engineering or technical requirement. In the example of automobiles, expectation of high power would technically mean generation of high torque by the engine, while expectation of high mileage would employ the technical need for a 4 stroke engine. QFD lets the designers know where their products or services stand vis--vis the competitors' products or services on the customer expectation profile. QFD aids in objectively determining which technical requirement implemented would result in maximum possible satisfaction of most customers. Also it lets the designers know which technical requirements if neglected completely and not implemented, would not affect the satisfaction level of customers much. QFD emerged as a useful tool manufacturing but also in services set-ups. Quality Function Deployment (QFD) has been used in Japan since 1966 to help companies better understand how their customers define quality, and then assure that the internal operations such as design and manufacturing can actually deliver it. QFD has been widely practiced by various divisions of Japanese competitors of ours such as NEC [Akao 1990, Takada 1992, Uchimaru et al., 1993] and Panasonic [Akao 1990], and even European [Olsson 1993, Jacobs 1996] and American ones [Bosserman and Stoner 1994, Bohem and Squires 1995, Richardson and Barnard 1996, Stickel and Bosserman 1996].
There are references to the application of this technique during the 1970's at Mitsubishi Heavy industries, by Komatsu, Fuzi, Isuzu, Konica and Matsushita. Yogi Akao (1972), presently a professor at Asahi University. Yogi Akao has been credited with developing this technique to the present form. In 1987, the QFD research group of the Japanese society of quality control (JSQC) led by Akao published a final survey report on the status of QFD application among 80 Japanese companies (Akao et al., 1987; 1989). The companies surveyed listed the following as the purpose of using QFD: setting design quality and planned quality; benchmarking competitive products; new product development that sets the company apart from competitors; analyzing and accumulating market quality information ; communicating quality related information to later processes; deploying design intent into manufacturing & identifying control points for the GEMBA (a Japanese term that refers to the place where source information can be learned); reducing initial quality problems, reducing design changes; cutting development time; reducing development costs & expanding the market share. In recent years, the more QFD-proficient of these companies have upgraded to Comprehensive QFD, which includes several tools to better analyze the Voice of the Customer, and more concise deployment matrices that address specific design requirements such as performance, function, technology, capability, as well as the components,