The customer satisfaction and customer dissatisfaction ratings attached to a requirement
the value the customer places on a requirement. The satisfaction rating measures how happy the customer will be if you success fully deliver an implementation of the requirement, and the dissatisfaction rating measures how
the customer will be if you do not successfully deliver this requirement. See Chapter 10, Writing the Requirements, for a discussion of customer satisfaction and customer dissatisfaction.
We have found that this two-step approach helps people to think more objectively about a requirement rather than mechanically giving it a number on a scale from one to ten or, even
, a high, medium, or low value.
See Chapter 14, Reviewing the Specification, for a discussion of how to use the customer value ratings to prioritize requirements.
You may decide to substitute Quality Function Deployment (QFD) for this exercise. QFD was developed by the Japanese car industry to ensure that all requirements are
"in the voice of the customer." QFD includes a matrix for identifying the customer importance rating. The difference between the customer importance rating and the customer value is that, rather than having one importance rating, customer value has two ways of rating each requirement.
The real test for the Quality Gateway is whether the requirement carries an appropriate rating of the value that the customer places on the requirement.
For a good summary of QFD, see Macaulay, Linda A.
Your customer, or a panel made up of the significant stakeholders, sets the ratings with your help. Later, these ratings are weighed against the cost of the requirement and, if necessary, used to help make choices between requirements and assign implementation priorities. Although this activity may seem to be something of an arduous exercise, knowing precisely what value to attach to a requirement is very worthwhile.
For more on customer satisfaction and dissatisfaction ratings, refer to Pardee, William J. To
Satisfy and Delight Your Customer.
New York, 1996.
If you have a large number of requirements that have a satisfaction/dissatisfaction rating of 5/5, then it indicates that the values have not been thoughtfully rated. As this process is the best opportunity your customer has of letting you know what is important and what is not, we suggest you reject the ratings and ask they be done again. Perhaps for the
rating exercise you should set a limitsay, 75 percentof the number of requirements that may have a "5/5" rating. Make sure that your customer understands your reason for doing so is to understand what is most important to his business; then if you need to make trade-offs, you can choose the most relevant ones. Another reason for attaching customer values to the requirement is to determine what is, and what is not, gold