In recent
years, many U.S. and Japanese firms have adopted Quality Function
Deployment (QFD). QFD is a total-quality-management process
in which the "voice of the customer" is deployed throughout
the R&D, engineering, and manufacturing stages of product development.
For example, in the first "house" of QFD, customer needs are
linked to design attributes thus encouraging the joint consideration
of marketing issues and engineering issues. This paper focuses
on the "Voice-of-the-Customer" component of QFD, that is, the
tasks of identifying customer needs, structuring customer needs,
and providing priorities for customer needs.
In the identification
stage, we address the questions of (1) how many customers need
be interviewed, (2) how many analysts need to read the transcripts,
(3) how many customer needs do we miss, (3) how many customer
needs do we miss, and (4) are focus groups or one-on-one interviews
superior? In the structuring stage the customer needs
are arrayed into a hierarchy of primary, secondary, and tertiary
needs. We compare group consensus (affinity) charts, a technique
which accounts for most industry applications, with a technique
based on customer-sort data. In the stage which provides
priorities we present new data in which product concepts
were created by product-development experts such that each concept
stressed the fulfillment of one primary customer need. Customer
interest in and preference for these concepts are compared to
measured and estimated importances. We also address the question
of whether frequency of mention can be used as a surrogate for
importance. Finally, we examine the stated goal of QFD, customer
satisfaction. Our data demonstrate a self-selection bias
in satisfaction measures that are used commonly for QFD and
for corporate incentive programs.
We close
with a brief application to illustrate how a product-development
team used the voice of the customer to create a successful new
product.
