Quality function deployment

Quality function deployment (QFD) is a “method wily 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.”, as described by Dr. Yoji Akao, who originally developed QFD in Japan in 1966, when 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.

QFD helps transform customer needs (the voice of the customer [VOC]) into engineering characteristics (and appropriate test methods) for a product or service, prioritizing each product or service characteristic while simultaneously setting development targets for product or service.

Areas of application

QFD House of Quality for Enterprise Product Development Processes

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 appeared in 1972 in the design of an oil tanker by Mitsubishi Heavy Industries. Akao has reiterated numerous times that a House of Quality is not QFD, it is just an example of one tool.

A Flash tutorial exists showing the build process of the traditional QFD "House of Quality" (HOQ). (Although this example may violate QFD principles, the basic sequence of HOQ building are illustrative.) There are also free QFD templates available that walk users through the process of creating a House of Quality.

Other tools extend the analysis beyond quality to cost, technology, reliability, function, parts, technology, manufacturing, and service deployments.

In addition, the same technique can extend the method into the constituent product subsystems, configuration items, assemblies, and parts. From these detail level components, fabrication and assembly process QFD charts can be developed to support statistical process control techniques.

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.

Notes

• "What is QFD?" - White paper explaining what QFD is and how to use it.
• Learn Quality Function Deployment (QFD)
• QFD Explained

References

• More About QFD Online, Quality Function Deployment On-line