Bug rate is the count of issues marked as bugs that were created after linked stories and/or issues were marked complete. This metric helps you understand the frequency of bugs identified after development of a story or issue.
HOW IT’S MEASURED
Bug rate is calculated per Epic by counting the number of issues with type:bug that were created after linked stories and/or issues were marked complete. Bug rate can also be represented as a percentage by dividing the number of bugs by the total number of stories or issues in an Epic.