What is it
Rate of completion of defects allocated to an interval.
Why it matters
Defect Rate helps teams get the right balance between working on new features relative to fixing defects. It also highlights how productive teams are completing assigned defects, and ensures progress is being made when defects are assigned to an interval.
We can often get excited about designing and building new features, but less excited about fixing the bugs we created along the way. A common pitfall for teams is to either get completely bogged down by bugs and clean-up and not progress any new feature work. And of course, the reverse is true, where teams are only building new features and ignore reducing their technical debt at their own peril. Umano created Defect Rate to help teams strike the right balance for them between time spent building new work with time spent fixing bugs and reducing technical debt. This helps teams be more strategic where they focus and more deliberate when shifting that focus to respond to changing priorities.
Ideally, the team is completing defects at the same rate by which they are assigned to the interval, or faster if there are new ones being assigned mid interval. Measuring a team's ability to remediate and complete defects also helps the team to track the rate of delivering new features relative to fixing defects.
What good looks like
Defect Rate is presented as a percentage and actual count of defects completed relative to all defects assigned, issues assigned and issues completed.
A good Defect Rate reflects a high rate of defects being completed relative to defects assigned. Good practices relating to your team’s Defect Rate also indicates a regular and consistent amount of defects being assigned and completed to your interval, relative to all issues assigned. This reflects a methodical practice of maintaining your code base and reducing technical debt.
How TeamX calculates it
There are three components to TeamX’s Defect Rate, each of which can be selected to be plotted on your chart:
All Defects Completed, relative to all defects assigned to an interval – the higher the percentage score indicates a higher productivity when completing assigned defects. For example, a percentage score of 60% indicates 60% of defects assigned to the interval were completed.
All Defects completed, relative to all issues completed in an interval – this is indicative of the defect vs feature focus in the work completed by your team. For example, a score of 60% indicates 60% of all issues completed were defects
All Defects assigned relative to all issues assigned to an interval – indicative of the defect vs feature focus in the work planned for your team. For example, a score of 60% indicates 60% of issues assigned were defects
TeamX presents each of these components as a percentage rate, or as an actual issue count.
For defects completed, TeamX surfaces the life cycle for each defect, including each status change, when the change occurred, who collaborated on the defect and the date the defect was completed.
For incomplete defects, TeamX surfaces the life cycle for each defect, including each status change, when the change occurred, who collaborated on the defect and how long the defect has been the last assigned status
Here's an example of how we calculate Defect Rate:
Get the total number of allocated bugs/defects in an interval and get the number of bugs/defects completed at the end of the interval/at present for an active interval. In this case:
Interval Start Time | Ticket ID | Ticket Type | Completed Time | Interval Completion Time |
2021-01-02 10:00:00 | MA-0001 | Story | 2021-01-03 10:00:00 | 2021-01-07 10:00:00 |
MA-0002 | Bug | 2021-01-02 16:00:00 |
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MA-0003 | Task | 2021-01-08 10:00:00 |
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MA-0004 | Bug | 2021-01-03 15:00:00 |
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MA-0005 | Bug |
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MA-0006 | Bug |
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Total number of defects = 4
Completed number of defects = 2
Defect rate = ((2/4)*100) = 50%
What's included when TeamX measures your team's Defect Rate?
Activities that contribute to and influence Defect Rate include all the issues assigned to the interval, including all bugs/defects assigned to the interval, and the status changes of each bug/defect in the active interval.
Driving Practices
Number of defects added mid-interval
Number of issues added mid-interval
Total number of issues in the interval
Number of issues completed
Total number of defects in the interval
Number of defects completed
Number of issues at start of interval
Number of defects at start of interval
Tips for improving your team's Defect Rate
When planning, set guardrails or targets that clearly state how your team will split its focus and time across both defects and new features to be created; this helps to maintain your code base and reduce technical debt over time. For example, your team might decide that 20% of each interval will be allocated to working on defects.
When planning how much capacity you spend working on defects, refer to this metric to understand how many of the defects you work on are usually planned vs unplanned; build in a buffer for unplanned defects if this is your usual way of working.
Help reduce the number of bugs introduced to your code base upstream with stronger review practices; refer to TeamX’s review workflow metrics for deeper insights into where your review practices might be letting you down