Quality Function Deployment (QFD) is an excellent tool to ensure linkage of customer needs to product requirements. This article will provide a high-level overview on creating a ‘first-level’ QFD and how it can be used to guide design optimization.
(There are many additional features of QFD , however, and readers of this article are encouraged to research the methodology further.)
As stated above, we use the QFD matrix (similar to a cause-effect matrix) to ensure linkage of customer needs to product requirements using the critical thinking / questions as follows:
Let’s dive right into a generic example of a filled-out QFD matrix:
This QFD suggests a value equation as follows:
Customer Value = 8.5*Req3 + 6.1*Req1 + 5.7*Req2 + 5.1*Req4 + 4.3*Req6….etc
How can we use equation? It depends on the requirement:
Your equation may not be perfect, but we at least have a mathematical relationship by which value can be estimated and tied to product performance and features. Also, our goal is to minimize product cost: an index CV/C could be maximized through the combination of a value equation and cost models (a design optimization model which enables trade-off decisions to be estimated for maximized value and minimized cost).
This article only scratches the surface on the topic…hopefully it provides the reader enough information on the concept of value equations and using mathematical relationships to enable optimized designs.