What is Quality Function Deployment?

Probably the most effective tool to translate customer requirements into design and manufacturing specifications is Quality Function Deployment (QFD). This method allows to systematically converting customer’s demands into technical requirements, for each stage of product development and production.  One of the greatest advantages of QFD is that it allows translating subjective quality criteria into objective criteria that can then be used to manufacture a product. In practice, the QFD process involves a cross-functional team putting together what is called a “House of Quality,” basically a double-entry table with customer requirements in the rows (the “voice of the customer”) and technical descriptors (“voice of the process”). The house of quality is then populated with information such as strength of relationships between customer requirements and process requirements, importance of requirements for customers, position of the company compared to the competition in each quality requirement, and current and target values for the technical descriptors listed. This process is then repeated for the different stages of the product development (quality characteristics, product characteristics, manufacturing process attributes, and production quality controls), and the technical requirements listed in one step become the customer requirements in the next. More detailed information can be found in Yoji Akao’s book [1]. The following figure shows an example.

Figure 1. House of Quality for a toothpaste container [2].

 

References

  1. Akao, Y., Quality function deployment : integrating customer requirements into product design. 1990, Cambridge, Mass.: Productivity Press. 387.
  2. Bahill, A.T. and W.L. Chapman, A tutorial on quality function deployment. Engineering Management Journal, 1993. 5(3): p. 24.