Think When/When

The Seven Habits of Highly Effective Testers
Part 4 of 7

This is the fourth post in a series which is based ever-so loosely on Stephen R. Covey's book but focused on what you can do to be more effective as a software tester.


This post is about defect triage. I first learned abut triage from watching M*A*S*H. When the choppers and ambulances would bring in the wounded, the doctors and nurses would assess the men and decide who needed to get surgical attention first. These decisions would be based on the severity of the wounds as well as what part of the body the was injured. So a massive leg wound might not get precedence over a moderate heart wound.

When deciding when defects should be fixed it should work the same way, but it often does not. That is because of the confusion between severity and priority. Generally severity is measured on a scale from Sev1 - Crash the system to SevX - No harm to foul.

The problem comes when severity is the only factor that is considered. In such a situation, a bug that crashes the system but only occurs through a very unlikely usage scenario will get fixed before a more moderate problem that happens in a common user flow. Also, important bugs that are not especially severe will be deferred.

This is just wrong.

A better way that more advanced teams use is to assign a priority to each defects. To determine this priority, many factors should be considered. First and foremost, is severity, which can be assessed by the person reporting the defect. Also to be included is the likeliness of the defect being encountered by users. This can be determined by the support team with perhaps some input from the marketing folks. Another factor is the current workload of the specific development resources needed to fix the problem. This system therefore requires stakeholders from across the project to be most effective.

When these other factors besides just severity are considered, you will come up with a much better answer to the question of "When should this defect be fixed?"


Previous Posts:
1 - Be Protractive
2 - Begin With the Vend in Mind
3 - Put Worst Things First

Next Up:
5- Seek First to Understand, Then to Exploit