Most people know interruptions are the bane of software development efficiency, but quantifying their cost can be challenging.
This report measures completed tickets that interrupted a sprint (added after start and completed before the end of the same sprint), and, for the first time, completed tickets that interrupted other tickets.
A ticket-level interruption is defined as follows:
This means that the person stopped what they were doing to complete the interrupting ticket, which is more disruptive than just adding it to the sprint and working on it after the current task.
To compute the total interruption overhead, a portion of the story points for sprint- and ticket-level interruptions is divided by the total points completed in each sprint.
You can set the multiplier for ticket and sprint interruptions, but this report uses 50% for ticket interruptions and 25% for sprint interruptions, for a maximum of 50% interruption overhead.
This report also shows the rate of sprint and ticket interruptions broken down by ticket priority. This view is useful to assess whether teams are actually using ticket priorities as intended.
If many low-priority tickets are causing interruptions, then people may not be setting the priority field to a higher level like they should.
On the other hand, if top-priority tickets aren't completed before other work, then teams may not be respecting priority levels as expected.