How to Classify Bug Severity in Your Bug Reports

Posted in: Bug reports, Quality assurance testing by: CheyleneT on:

This is the fourth article in the series on Bug Reports. Click here to read the next article: reporting related bugs


So you’ve found a bug – now what? Well, after you’ve documented its details, the next step is to evaluate the bug severity. While it can be summed up in one word, severity is a very integral part of the overall bug report. Get it right and the development team can allocate the appropriate amount of time and effort to each issue. Get it wrong and you risk hampering the development life cycle. Though the exact terminology may differ between organizations and projects, there are some general guidelines to follow when determining whether a bug is trivial, minor, major or critical.


Trivial bugs are common and probably the easiest to identify. As a general rule, they have no real impact on the functionality of the application you’re testing. Trivial defects often come in the form of cosmetic or design errors, such as a text block exceeding its boundaries or an image out of alignment. This would be classified as minor on the bug severity scale.


Minor defects are a little trickier to classify. While they still should not impede an application’s primary features or functionality, minor bugs will have a greater adverse impact than their trivial counterparts. For example, if you are testing an application and trigger a pop-up message that is incorrect – or even in the wrong language – this is a minor defect, so long as it has no effect on the general functionality of the application itself.


As you test an application, you should always have its requirements and/or user stories in mind. If you encounter an issue that prevents the application from meeting requirements or carrying out a feature, it classifies as a major bug on the bug severity scale. In most cases, major bugs are fairly obvious. For instance, if you are testing a game and the application fails to save your score the next time you login, then that is a major bug. Another example would be if the shopping cart function of an e-commerce app does not correctly tally totals and subtotals. In short, major issues prevent applications from doing what they were specified to do.


Critical bugs, or showstoppers as they are often called, are so severe that they prevent you from further testing. These issues manifest themselves in a number of different ways. They can range from an app that continuously crashes to a button missing in the user interface preventing you from loading or triggering a required part of the application. Critical bugs are the highest on the bug severity scale.

bug severity

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Final thoughts on bug severity

Before you make a final decision on the severity of a defect, evaluate how the issue impacts the user experience. If the defect is something that hurts the usability, but not functionality, you are dealing with a trivial or minor bug. If a defect causes an application to deviate significantly from its core functionality, it should most likely be classified as major. Reserve the critical classification for issues that veer the testing process off course completely.

This is the fourth article in the series on Bug Reports. Click here to read the next Bug Reports article on: reporting related bugs