Quality function deployment
Quality function deployment (QFD) is a method to help transform customer needs (the voice of the customer [VOC]) into engineering characteristics (and appropriate test methods) for a product or service. It helps create operational definitions of the requirements, which may be vague when first expressed. It prioritizes each product or service characteristic while simultaneously setting development targets for the product or service.
As described by Dr. Yoji Akao, who originally developed QFD in Japan in 1966, it is a “method to transform qualitative user demands into quantitative parameters, to deploy the functions forming quality, and to deploy methods for achieving the design quality into subsystems and component parts, and ultimately to specific elements of the manufacturing process.”, The author combined his work in quality assurance and quality control points with function deployment used in value engineering.
QFD is designed to help planners focus on characteristics of a new or existing product or service from the viewpoints of market segments, company, or technology-development needs. The technique yields charts and matrices.
Areas of application
QFD is applied in a wide variety of services, consumer products, military needs, and emerging technology products. The technique is also included in the new ISO 9000:2000 standard which focuses on customer satisfaction.
While many books and articles on "how to do QFD" are available, there is a relative paucity of example matrices available. QFD matrices become highly proprietary due to the high density of product or service information found therein.
Techniques and tools based on QFD
House of Quality
House of Quality is a diagram, whose structure resembles that of a house, which aids in determining how a product is living up to customer needs. Although quite intricate, it is capable of storing a lot of information and comparing large amounts of data used for defining the relationship between customer desires and the firm/product capabilities. It is a part of the Quality Function Deployment (QFD) and utilizes a planning matrix to relate what the customer wants to how a firm (that produces the products) is going to meet those wants. It looks like a house with a "correlation matrix" as its roof, customer wants versus product features as the main structure, competitor evaluation as the porch, etc. It is based on "the belief that products should be designed to reflect customers' desires and tastes". It also is reported to increase cross functional integration within organizations using it, especially between marketing, engineering and manufacturing.
The basic structure is a table with "Whats" as the labels on the left and "Hows" across the top. The roof is a diagonal matrix of "Hows vs. Hows" and the body of the house is a matrix of "Whats vs. Hows". Both of these matrices are filled with indicators of whether the interaction of the specific item is a strong positive, a strong negative, or somewhere in between. Additional annexes on the right side and bottom hold the "Whys" (market research, etc.) and the "How Muches". Rankings based on the Whys and the correlations can be used to calculate priorities for the Hows.
House of Quality analysis can also be cascaded, with "Hows" from one level becoming the "Whats" of a lower level; as this progresses the decisions get closer to the engineering/manufacturing details.
A Flash tutorial exists showing the build process of the traditional QFD "House of Quality" (HOQ).
Pugh concept selection
Pugh Concept Selection can be used in coordination with QFD to select a promising product or service configuration from among listed alternatives.
Modular Function Deployment
Modular Function Deployment uses QFD to establish customer requirements and to identify important design requirements with a special emphasis on modularity. There are three main differences to QFD as applied in Modular Function Deployment compared to House of Quality:
- The benchmarking data is mostly gone.
- The checkboxes and crosses have been replaced with circles.
- The triangular “roof” is missing.
There are also other minor differences between the application of QFD in Modular Function Deployment as compared to House of Quality, for example the term "Customer Attribute" is replaced by "Customer Value", and the term "Engineering Characteristics" is replaced by "Product Properties". But the terms have similar meanings in the two applications.
Relationship to other techniques
Quality Function Deployment is closely related to Hoshin Kanri. The Hoshin process came before QFD and both are used to document the objectives and needs of an organization.
- Akao, Yoji (1994). "Development History of Quality Function Deployment". The Customer Driven Approach to Quality Planning and Deployment. Minato, Tokyo 107 Japan: Asian Productivity Organization. p. 339. ISBN 92-833-1121-3.
- http://www.c2c-solutions.com/pdfs/eQFDRoadmap.pdf QFD/DFSS Roadmap and flowchart
- Börjesson, Fredrik; Jiran, Scott. "The Generation of Modular Product Architecture Deploys a Pragmatic Version of Quality Function Deployment". Retrieved 2 November 2012.
- "What is QFD?" - White paper explaining what QFD is and how to use it.
- Learn Quality Function Deployment (QFD)
- QFD Explained
- More About QFD Online, Quality Function Deployment On-line