Bugs Severity and Priority Classification

Defect Classification According to the Degree of Bug Severity

Blocker. An error that renders the program unusable. Further work with the software system or its functions is impossible.

Critical. A critical defect that renders some key functionality inoperative. It can also be a significant deviation from the business logic, incorrect implementation of the required functions, loss of user data, etc.

Major. A serious error indicating a deviation from the business logic or disrupting the program. Has no critical impact on the application.

Minor. A minor defect that does not violate the functionality of the tested application, but does not match the expected result. For example, a design error.

Trivial. A bug that can be detected visually but does not affect  the functionality or work of the program. For example, a text error.

Priority Classification

High. The bug must be fixed as soon as possible as it critically affects the performance of the program.

Medium. The defect must be fixed, but it does not have a critical impact on the application.

Low. The bug should be fixed, but it does not have a critical impact on the program and the elimination may be postponed, depending on the presence of other higher priority defects.

This classification is used to organize the work of many bug tracking systems, including Jira. By becoming familiar with these terms, you can better understand the life cycle of a defect, which is a necessary step towards becoming a tester.