Software Engineering for Students A Programming Approach

29.7 Process improvement 365
specify what methods they are using. In addition, the organization must demonstrate
that they are using the methods. Thus an organization must not only use sound methods
but must be seen to be using them. Therefore a quality plan describes a number of
quality controls. A quality control is an activity that checks that the project’s quality factors
are being achieved and produces some documentary evidence. In the kitchen, an
example is an inspection carried out after potatoes have been peeled. The documentary
evidence is the signature of the chief cook on a checklist recording that this has been
done. These documents are then available to anyone – such as the customer – with an
interest in checking that the quality of the product is assured. Depending on the quality
factors for the project, quality controls might include:
Action Document Factor being checked
Collect a complexity metric Data on complexity Maintainability
for each component in the system
Component test Test result Correctness
Walkthrough to examine component Minutes of walkthrough Reusability
for re-usability
SELF-TEST QUESTION
29.4 What quality factors would the measurement of fault density help
achieve?
29.7 ● Process improvement
We have seen how quality can be measured, attained and ensured. A more ambitious
goal is to improve quality. One perspective on improving quality is suggested by
W. Edwards Deming, an influential management guru, who suggests that processes can
be continuously improved. In his approach, the work processes are subject to continuous
examination by the workers themselves as well as the organization in order to see
how things can be done better.
So, for example, suppose that the number of faults discovered during testing is measured.
But simply measuring does not achieve anything; measurements may help to
ensure repeatability, but this is not the same as improvement. To improve the process,
someone looks at how and why the faults were caused and what can be done to improve
the processes. So, for example, it might be that a significant number of faults arise
because of lack of clarity in module specifications. Therefore, to improve the process it
might be decided that module specifications should be subject to walkthroughs before
they are used. Alternatively it might be suggested that a more formal notation is to be