Severity Vs Priority (Defect)

Severity: Severity means the impact of defect on the application. Severity is generally decided by the tester. Severity shows the failure of application.

Priority: Priority means when a defect should be fixed. Priority is generally decided by the business. Priority shows order of fixing of defect.

When a project enters test execution, the focus will be on fixing defects of the highest priority. This means that the application will be released with the minimum amount of priority defects unresolved. Care should be taken by the Project Manager to ensure that whilst the priority is paramount, severity is not ignored. What is needed is a balanced approach, which favours the business priority. At the end of the project the volume of high severity and high priority defects should have at least been reduced, if not removed, in order to meet the exit criteria defined in the test strategy.

Example of low severity and high priority

If you are at home page of a company site and at the top you observe that name of the company is spelled wrong then severity is very low because it is not causing any functionality failure or application crash. But priority in this case will be very high as it gives bad impression and visible to all who access that site.

Example of high severity and low priority

An inability to access a rarely used menu option may be of low priority to the business, but the severity is high as a series of tests cannot be executed, all dependent on access to the option.