Quality Function Deployment (QFD)

Quality Function Deployment is a method for prioritizing and translating customer inputs into designs and specifications for a product, service, and/or process. While the detail of the work involved in QFD can be both complex and exhaustive, the essentials of the QFD method are based on common-sense ideas and tools. QFD is a planning tool that relates a list of delights, wants, and needs of customers to design technical functional requirements.

With the application of QFD, possible relationships are explored between quality characteristics as expressed by customers and substitute quality requirements expressed in engineering terms. In the context of DFSS, these requirements critical-to characteristics, which include subsets such as critical-to-quality (CTQ) and critical-to-delivery (CTD). In the QFD methodology, customers define the product using their own expressions, which rarely carry any significant technical terminology. The voice of the customer can be discounted into a list of needs used later as input to a relationship diagram, which is called QFD’s house of quality.

One major advantage of a QFD is the attainment of shortest development cycle, which is gained by companies with the ability and desire to satisfy customer expectation. The other significant advantage is improvement gained in the design family of the company, resulting in increased customer satisfaction. QFD is a robust method having many variations in applications, as

• Prioritize and select improvement projects based on customer needs and current performance
• Assess a process’s or product’s performance versus competitors
• Translate customer requirements into performance measures
• Design, test, and refine new processes, products, and services

QFD uses various other methods like Voice of the Customer input to Design of Experiments, to work well. A special multidimensional matrix, also called as the “House of Quality,” is the best-known element of the QFD method. A full QFD product design project will involve a series of these matrices, translating from customer and competitive needs to detailed process specifications. QFD concept involves two core concepts, which are

The QFD Cycle – An iterative effort to develop operational designs and plans in four phases of

• Translate customer input and competitor analysis into product or service features.
• Translate product/service features into product/service specifications and measures.
• Translate product/service specifications and measures into process design features.
• Translate process design features into process performance specifications and measures.