Severity vs. Priority in Software Testing


Error severity or defect severity in testing is the degree of impact of the defect or defect on the application being tested. A higher impact of the error/failure on the functionality of the system results in a higher severity level. The quality assurance engineer usually determines the severity of the defect/failure.


Priority is defined as the order in which faults are fixed. The higher the priority, the faster the error should be fixed. Defects that render a software system unusable are more serious than errors that cause minor software malfunctions.

Difference between Severity and Priority

1Defect Priority has defined the order in which the developer should resolve a defectDefect Severity is defined as the degree of impact that a defect has on the operation of the product
2Priority is categorized into three typesLowMediumHighSeverity is categorized into five typesCriticalMajorModerateMinorCosmetic
3Priority is associated with schedulingSeverity is associated with functionality or standards
4Priority indicates how soon the bug should be fixedSeverity indicates the seriousness of the defect in the product functionality
5Priority of defects is decided in consultation with the manager/clientQA engineer determines the severity level of the defect
6Priority is driven by business valueSeverity is driven by functionality
7Its value is subjective and can change over some time depending on the change in the project situationIts value is objective and less likely to change
8High priority and low severity status indicates, the defect has to be fixed on immediate bases but does not affect the applicationHigh severity and low priority status indicate defect has to be fixed but not on immediate bases
9Priority status is based on customer requirementsSeverity status is based on the technical aspect of the product
10During UAT the development team fixes defects based on priorityDuring SIT, the development team will fix defects based on the severity and then the priority

A real-life example of Severity and Priority

Let’s take an example of two patients reached a doctor at the same time:

Patient A: He is suffering from a cold.

Patient B: He is suffering from chest pain.

Now the doctor needs to decide on whom he should attend first. Based on the issue both patients are facing doctor will first diagnose Patient B as the issue with him is of high severity and the priority of Patient B will become high.

Example of Severity and Priority

1A very low severity with a high priorityA front-facing webpage is not showing the company logo.
2A very high severity with a high priorityA customer order a Web Camera but in the backend two duplicate orders are created and sent to the delivery center for processing.
3A very low severity with a low priorityA typo on a webpage that is not front facing to the customer.
4A very high severity with a low priorityAn admin page that is showing server error but is not a very commonly used feature by all admins.

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