Quality Function Deployment (QFD) Getting from the voice of the customer to technical design specifications

Four Important Points to Understand Before Implementation of QFD 1. No matter how well the design team thinks it understands the problem, it should employ the QFD method for all design projects. In the process the team will learn what it doesn’t know about the problem.

2. The customer’s requirements must be translated into measurable design targets. You can’t design a car door that is “easy to open” when you don’t know the meaning of the word “easy”. 3. The QFD method can be applied to the entire problem and/or any subproblem. 3. The QFD method can be applied to the entire problem and/or any subproblem.

4. It is important to worry about what needs to be designed and, only after this is fully understood, to worry about how the design will look and work.

Our cognitive capabilities generally lead us to try to assimilate the customer’s functional requirements (what is to be designed) in terms of form (how it will look); these images then become our favored designs and we get locked into them. The QFD procedure helps us to overcome this cognitive limitation.

The Quality Function Deployment (QFD) Technique 1. Identifying the Customer(s). 2. Determining Customer Requirements. 3. Prioritizing the Requirements. 4. Competition Benchmarking. 5. Translating the Customer Requirements into Measurable Engineering Requirements.

Step 1: Identifying the Customer(s) Who is the customer? In addition to the person buying the product, the customers of the design engineer would also include the manufacturing and assembly engineers and workers. (or anyone else downstream of the design process).

Step 2: Determining Customer Requirements The goal is to develop a list of all the customer requirements (made up in the customer’s own words) that will affect the design. This should be accomplished with the whole design team, based on the results of customer surveys.

Step 3: Prioritizing the Requirements A weighting factor is generated for each requirement. The weighting factor will give the designer an idea of how much effort, time and money to invest in achieving each requirement.

Two questions should be addressed in developing a prioritization  (1) To whom is the requirement important?  (2) How is a measure of importance developed for this diverse group of requirements?

Step 4: Competition Benchmarking  The goal here is to determine how the customer perceives the competition’s ability to meet each of the requirements. This forces awareness of what already exists and points out opportunities for improving upon that which already exists.  Each competing product is compared with customer requirements. Some comparisons are objective and others are subjective.

Step 5: Translating the Customer Requirements into Measurable Engineering Requirements The goal here is to develop a set of engineering requirements (often called design specifications) that are measurable for use in evaluating the proposed designs.  1. transform the customer requirements into engineering requirements and  2. make sure that the engineering requirements are measurable.