The House of Quality
QFD is applied across all the sequential phases
for developing a product/service like product/service planning,
design planning, process planning and production planning.
Each phase is represented in a QFD matrix, also called as
the 'House of Quality'.
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The left side of the above matrix consists
of the customer requirements or the Voice of the Customers
(the Whats). This is a structured list of requirements
obtained through customer feedback, market research and
benchmarking studies
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The top of the matrix consists of the
organisation's requirements or the Voice of the Company,
(the Hows) which is a structured set of relevant and measurable
product characteristics.
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The right side of the matrix gives the
planning considerations to give the outputs (the Whys).
This illustrates customer perceptions observed in market
surveys. Includes relative importance of customer requirements,
company and competitor performance in meeting these requirements.
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The centre of the matrix describes the
relation between customer requirements and design requirements.
This illustrates the QFD team's perceptions of interrelationships
between technical and customer requirements. An appropriate
scale is applied, illustrated using symbols or figures.
Filling this portion of the matrix involves discussions
and consensus building within the team and can be time
consuming. Concentrating on key relationships and minimising
the requirements are useful techniques to reduce the demands
on resources.
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The top most part or the triangular roof
of the matrix represents the fourth phase (inter-relationships
between the technical descriptors). This is used to identify
where technical requirements support or impede each other
in the product design. Can highlight innovation opportunities
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The bottom of the matrix indicates the
targets. It is used to record the priorities assigned
to technical requirements by the matrix, measures of technical
performance achieved by competitive products and the degree
of difficulty involved in developing each requirement.
The final output of the matrix is a set of target values
for each technical requirement to be met by the new design.
These are linked back to the customers' demands.
The "House of Quality" can be used
as a stand-alone tool to generate answers to a particular
development problem. Alternatively it can be applied within
a more complex system in which a series of tools are applied
for each stage of the product/service development. The outputs
of the first stage give the product/ service design specifications
(the Hows). These in turn form the inputs (or whats) for
the second stage of development. This sequence repeats at
every stage and the outputs of the fifth and final phase
are the production requirements for the product/service.
QFD… overcomes functional barriers
Throughout this multi-phase approach, all
members of the QFD team (design, manufacturing, marketing,
Quality Control) are able to understand the manner in which
their individual inputs contribute to meet and satisfy customer
requirements. This helps to improve and overcome inter-departmental
functional barriers resulting in better communication and
faster processes.
Using QFD facilitates collection of all data
required to generate good production definition, design,
processes, and production and delivery decisions early in
a project. The data and the inter-relationships between
requirements, specifications and other activities to evolve
the final product/service are presented in a highly visible
form and this communicates the overall plan effectively.
