ME 102B QFD

## ME 102B Important Issues - QFD (Quality Function Deployment)

• QFD
• "method to transform user demands into design quality, to deploy the functions forming quality, and to deploy methods for achieving the design quality into subsystems and component parts, and ultimately to specific elements of the manufacturing process"

Very effective
Formal method to attain customer requirements and transform them into engineering requirements
Handy way to visual many forms of information in one chart (customer requirements, competition, engineering requirements, target values, requirement relationships)

• Step 3: Determining Relative Importance of the Requirements

• To whom is the requirement important?
How is a measure of importance developed for this diverse group of requirements?
Identify what customers you are going to please and in what order
Identify all the requirements that are "absolute must" (not all requirements are necessary for the product to be acceptable) In the weighting column of the QFD indicate these requirements with an asterisk.
All the remaining requirements are considered "wants" (these are the requirements that if they can be achieved it would be nice. There will be tradeoffs on many of these so it is necessary to know what order of importance each has. The "wants" are ranked or weighted and this can be a difficult step to assign objective weightings.

Proposed Ranking System
Make a chart with all of the requirements
Compare two requirements at a time. Give the more important requirement a 1 and the less important requirement a 0.
Compare all requirements
Sum totals for each requirement
Find the total number of comparisons = N x (N-1)/2
Divide totals for each requirement by number of combinations resulting in a percentage. This is the weight of the requirement.
Enter weight of requirement into QFD chart

• Step 4: Competition Benchmarking

• Goal: To determine how the customer perceives the competition's ability to meet each of the requirements. This will help force awareness of what already exists and point out opportunities to improve on what already exists. Want to Compare Competing Products or Alternatives with Customer Requirements. One way is to enter into QFD a value on scale of 1 to 5
1. Design does not meet the requirement at all
2. Design meets the requirement slightly
3. Design meets the requirement somewhat
4. Design meets the requirement mostly
5. Design fulfills the requirement completely

• Step 5: Translating Customer Requirements into Measurable Engineering Requirements

• Goal: To develop a set of engineering requirements that are measurable for use in evaluating proposed product designs
Must transform customer requirements to engineering requirements
Make sure engineering requirements are measurable
Enter units into QFD for each engineering requirement (If units for an engineering requirements cannot be found, then the requirements is not measurable and needs to be readdressed)
Fill in center portion of QFD form. Each cell of the form represents how each engineering requirement relates to each customer requirements. The strength of this relationship can vary with some engineering requirements providing strong measures for a customer's requirements and others providing no measure at all
Suggestions:
9 Strong relation
3 Medium relation
1 Weak relation
Blank no relation at all

• Step 6: Setting Engineering Target for the Design

• Goal: To determine target values for each of the engineering measures. Good to also to set value curves so you know the impact of values slightly out of the range
How does the competition meet the engineering requirements. This can also help to come up with target values for the new product
Set values for new product. Best to pick a specific number. However, valid to set a range or inequality. This also helps as a check to make sure that customer's wish list is reasonable. If their target values are very different from competition, be suspicious. Be careful to set reasonable target values.

• QFD in 6 Steps