Quality Function Deployment (QFD) or another type of requirements
definition process must be used to define the requirements or technical
characteristics of a product. A more complete specification may be
prepared. These requirements, specifications or technical characteristics
are then used as the basis for developing various product concepts.
Product benchmarking, brainstorming, and research and development are
sources for new product concepts. Once concepts are developed, they are
analyzed and evaluated. Cost studies and trade studies are performed. The
concept selection matrix can be used to help with this evaluation process.
This overall process is shown below:
The concept selection matrix shown below lists the
product requirements or technical characteristics down the left side of
the matrix. The technical characteristics are derived from the QFD product
planning matrix. The concept alternatives are listed across the top. Each alternative is rated
on how well it meets the technical characteristics or requirements.
The concept selection matrix and this process is part of DRM Associates'
QFD training and software package.
The specific steps for concept development and
selection are as follows:
- Based on the product requirements for technical
characteristics, develop concept alternatives for the new product.
Consider not only the current approach and technology, but other
alternative concept approaches and technology. Use brainstorming.
Conduct literature, technology, and patent searches. Use product
benchmarking to identify different product concepts. Develop
derivative ideas. Perform sufficient definition and
development of each concept to evalaute against the decision criteria
determined in the next step.
- Evaluate the concept alternatives using the
Concept Selection Matrix. List product requirements or technical characteristics from
the Product Planning Matrix down the left side of the Concept
Selection Matrix. Also add other requirements or decision criteria such as key
unstated but expected customer needs or requirements, manufacturability requirements,
environmental requirements, standards and regulatory requirements, maintainability
/ serviceability requirements, support requirements, testability requirements, test
schedule and resources, technical risk, business
risk, supply chain capability, development resources,
development budget, and development schedule.
- Carry forward the target
values for the product requirements or technical characteristics from the
Product Planning Matrix. Add target
values as appropriate for the other evaluation criteria added in the previous
step. Also bring forward the
importance ratings and difficulty ratings associated with each product requirement
or technical characteristic from the Product Planning
Matrix. Normalize the importance rating by
dividing the largest value by a factor that will yield "5" and post this
value to the "Priority" column. Review
these priorities and consider any changes appropriate since these are the
weighting factors for the
decision criteria. Determine the priorities for the additional evaluation criteria added in
the prior step. List concepts across the top of the matrix.
- Perform engineering analysis and trade studies. Rate each
concept alternative against the criteria using a
"1" to "5" scale with "5" being
the highest rating for satisfying the criteria.
- For each rating, multiply the rating by the "Priority" value in that
row. Summarize these values in each column in the bottom row.
The preferred concept alternative(s) will be the one(s) with the highest
- For the preferred concept alternative(s), work to improve the concept
by synthesizing a new concept that overcomes its weaknesses. Focus attention on
the criteria with the lowest ratings for that concept ("1's" and
"2's"). What changes can be made to the design or formulation
of the preferred concept(s) to improve these low ratings with the product
concept? Compare the preferred concept(s) to the other concepts that
have higher ratings for that particular requirement. Are there ways to
modify the preferred concept to incorporate the advantage of another concept?