Page 126 - Design for Six Sigma for Service (Six SIGMA Operational Methods)

Chapter
6

Quality Function Deployment

6.1 Introduction

In the context of Design for Six Sigma (DFSS), quality function deployment
(QFD) is best viewed as 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 expressed by customers and substitute quality requirements
expressed in engineering terms (Cohen 1988, 1995; Clausing 1994). In the
context of DFSS, we will call these requirements critical-to characteristics,
which include subsets like critical-to-quality, and critical-to-delivery char-
acteristics. In the QFD methodology customers define the product using
their own expressions which usually do not carry any significant technical
terminology. The voice of the customer (VOC) can be discounted into a list
of needs used later as input to a relationship diagram, which is called QFD’s
house of quality.

Knowledge of customer needs is a must requirement in order for a company
to maintain and increase its position in the market. Correct market predictions
are of little value if the requirements cannot be incorporated into the design at
the right time. Critical-to-innovation and critical-to-market characteristics are
critical because companies that are first to introduce new concepts at six-
sigma (6σ) levels usually capture the largest share of the market. Wrestling
market share away from a viable competitor is more difficult than wrestling
market share away from a first producer into a market. One major advantage
of a QFD is attainment of the shortest development cycle, which is gained by
companies with the ability and desire to satisfy customer expectations.
Another significant advantage is the improvement gained in the design family
of the company resulting in increased customer satisfaction.
The team should take the time required to understand customer wants and to
plan the project more thoughtfully. Using QFD, the DFSS team will be able

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