It is reasonably easy to define measurements and metrics for any particular organization or project. The bigger question is whether those metrics are relevant to the project and work at hand.
Metrics or Measurements Specific to Quality Control
- Number of tests
- Number of defects
- Defects per module
- Percent of tests completed
The above are fairly obvious examples of metrics and are quite frequently gathered along with a number of others as Quality Control and Quality Assurance data. Many of the test tools supplied commercially or available as Open Source gather one or more of these measurements automatically and make them available on graphs and in spreadsheets for manipulation.
Metrics or Measurements Specific to Quality Assurance
- Number of processes in place
- Degree of Acceptance of a process
- Effectiveness of any process
- Unmeasured processes
The above metrics vary from easy-to-gather and maintain to almost impossible to accurately estimate. They usually do not depend on any particular project although they may be department dependent based on the level of detail. However, we find that most organizations, while using many processes with varying degrees of effectiveness rarely make a concerted attempt to measure them. It is very tempting to simply use the process without considering whether or not it could be improved.
The key questions to ask are as follows
- Can the metric or measurement be gathered? (Preferably without impacting the test or quality effort.
- Are the figures accurate? (This needs to be tested just like the application.)
& Most important
- Are we making use of the metric to provide information to the project or organization?
The reason that we place such emphasis on the last point is that we encounter far too many instances where metrics and measurements are being gathered with no clear idea of why or how they can be used.
- Do you want to know if your processes are effective?
- Do you want to know if your processes can be improved? (And how to do it)
- Do you want to know how you compare to other organizations?
Next week we will discuss using Metrics.