Software Testing - Severity & Priority

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Software testing often leads to the detection of defects. The most critical properties associated with defects are known as their severity and priority. In this way, it guides the developers to resolve bugs faster within the project timelines and reduce defect leakages in production.

What is the Severity of a Defect?

The severity is the scale at which a specific defect can affect a software. It is a measure of how much the defect can affect the software and influence its functionalities. If a defect has a bigger functional impact on the software it is called a high severity defect. The severity of a defect is decided by the tester.

Types of Severity of a Defect

The different types of defect severity are listed below −

Blocker

If a defect is marked as blocker, it means that it is impacting everything and testers cannot proceed to test the next modules and need to wait till the blocker bug is fixed. For example, the login feature of the software is not working.

Critical

If a defect is marked as critical, it means that it is impacting one of the most critical software features, and the tester is unable to verify that feature at all. For example, the payment is not getting processed for all types of transactions in the e-payment software.

Major

If a defect is marked as major, it means that it is impacting one of the components of software, but the tester is not totally blocked and he is able to verify the other components. For example, in a banking application, the credit card processing feature is not working, however the testers can continue verifying the debit card functionalities.

Medium

If a defect is marked as medium, it means that there is a deviation observed in the software but the whole of it is working fine. For example, in an application, a specific dropdown is not working.

Minor

If a defect is marked as minor, it means that the error encountered does not bring any severe damage to the software.

What is the Priority of a Defect?

The priority of defects is the measurement that determines the sequence in which they should be resolved. A defect which is assigned with a higher priority number should be worked upon and fixed at first. The errors in the software which make it totally unusable for the end users has a higher priority.

Types of Priority of a Defect

The different types of defect priority are listed below −

High

If a defect is marked as high, it means that it should be rectified at the earliest as it is impacting the software very badly and it can not be used anymore.

Medium

If a defect is marked as medium, it means that it should be rectified before the release of the present version of the software.

Low

If a defect is marked as low, it means that it should be rectified provided there is enough time, else it can be deferred to the next release.

The testers assign both the severity or priority to defects, however a developer can modify a defect severity by providing sufficient evidence. However, a developer cannot update the priority of defects.

Difference Between Severity and Priority of Defects

Examples of Priority and Severity Defects

High Priority and High Severity Defect

Let us take an example, where once the tester hits the URL, a different application is launched instead of the one which is as per the requirement. The defect logged for this issue should have high severity since the entire application is inaccessible and the testers are totally blocked. Also, it should have high priority since it is highly affecting the business and customer needs, and should be resolved at the earliest.

High Priority and Low Severity Defects

Let us take an example, where the logo of the software is incorrectly shown. The defect logged for this issue should have low severity since this deviation is hardly impacting any other functionalities however, it should have a high priority since it is highly impacting the business requirements of the software.

High Severity and Low Priority Defects

Let us take an example, where the beta version of the e-commerce application is made available to only a handful of users. While testing this, it is seen that one of the most important functionality of searching desired products using the product search functionality is not working. The tester will log a defect which is of high severity but since it has affected only a few customers, its priority should be low.

Low Severity and Low Priority Defects

Let us take an example, where some text at the footer section of the software is having a typo error. The tester will log a defect of low severity since a type error at the footer section is not affecting a major functionality. It should also have a priority set to low as very limited users will scroll down and detect a typo error in the footer.

What is the Defect Triage?

A defect triage meeting is conducted by the product owners, testing team etc to prioritize defects in terms of functionality, severity, risks, etc. Each of the defects are reviewed and assessed. Based on that, the defects are identified with their priority, severity and assigned to the correct release by the product managers.

Defect triage is mainly followed in agile development projects. The frequency of conducting defect triage meetings depend on project size and its progress, number of defects logged, how the resource alignment may impact the project timelines etc.

Conclusion

This concludes our comprehensive take on the tutorial on Software Testing - Severity & Priority. We’ve started with describing what is severity of a defect, what are the types of severity of a defect, what is priority of a defect, what are the types of priority of a defect, what are the differences between severity and priority of a defect, examples of priority and severity of defects, and what is defect triage.

This equips you with in-depth knowledge of Software Testing - Severity & Priority. It is wise to keep practicing what you’ve learned and exploring others relevant to Software Testing to deepen your understanding and expand your horizons.