Quality function deployment (QFD) is the translation of user requirements and requests into product designs. The goal of QFD is to build a product that does exactly what the customer wants instead of delivering a product that emphasizes expertise the builder already has.
QFD was created by Japanese planning specialist Yoji Akao in 1966 as a way to help product planners look at new (or in-development products) through the lenses of customer, company and technology. QFD is achieved by linking the needs of the end user to subsystems or specific elements of the product creation process -- from design and development to engineering, manufacturing and services.
Visual representations of market needs are key components of QFD, and graphs and matrices are typically deployed to track the process. For instance, Six Sigma QFD requires the customer to document his needs and wants in his own words so that a "House of Quality" matrix can be built. The customer meets with the manufacturer to prioritize requirements so the manufacturer understands priorities and can translate them into engineering and business process requirements. The manufacturer then establishes design criteria to ensure the customer's requirements are met.
This video from QIMacros illustrates a QFD House of Quality matrix.