Severity and Priority in Software Testing

Severity and priority plays an important role while triaging any defect. Therefore assigning appropriate severity and priority is crucial while writing a good defect report. This not only helps in categorizing the defect, but it also actually makes defect tracking a whole lot easier task.Severity And PriorityHowever as it happens, both these terms are often confused and used interchangeably by testers. This article intends to shed some light on these concepts. So let’s start by understanding what is severity first.

Severity

Definition:

Severity can be defined as how severe the defect is to the system and how badly it will affect the functionality. For example, an application crash on clicking a button is severe to the system. So its severity will be high. Whereas a spelling/grammatical error will not have much impact on the overall functionality. So its severity will be low.

Levels:

Although this varies from company to company, there are generally 4 levels of severity.

  • Showstopper: A defect of this severity generally blocks testers from testing further. Hence the name showstopper. An example of a showstopper defect: A mobile app crashing on splash screen.
  • Severe: A defect of this severity breaks the important feature. However, tester can test other features fine. Let’s understand this using a defect found in user registration scenario. Although user is successfully registered in system, web page crashes on clicking Submit button and registration confirmation mail is not sent. Due to this defect, a tester would probably be able to test other features such as Login and Profile fine. But since the registration is broken, this defect would be severe to the system.
  • Moderate: A defect due to which application behavior deviates from what is expected but system as a whole is usable. For example, a validation failure for any important text field.
  • Minor: A defect of this severity doesn’t impact the functionality much. Nonetheless it should be fixed. Some examples: A spelling/grammatical errors, UI alignment issues.

Important concepts:

  • Severity is generally assigned by testers as they are better able to judge the impact of defect on a system.
  • Severity is not likely to change over the period of time.

Priority

Definition:

Priority can be defined as how fast or how early the defect should be addressed. The defects having highest priority should be fixed first followed by the defects having lesser priority.

Levels:

As with severity, priority levels may also differ in different companies. However it can be broadly classified in 3 levels.

  • High (Priority 1/P1): A defect which causes a significant damage to application is given a high priority. Defects having high priority should be fixed as soon as possible.
  • Medium (Priority 2/P2): Defects having medium priority should be fixed once high priority defects are addressed. Fixing of normal priority defects takes precedence over low priority defects.
  • Low (Priority 3/P3): Defects with low priority doesn’t impact the functionality much and they should be fixed once high and medium priority defects are addressed.

Important concepts:

  • Managers/Leads/Clients generally specifies the defect priority.
  • Priority of any defect is decided based on its business value. A business value may be client’s brand name and reputation, process standards or importance of functionality.
  • As the project progresses, priority may change as per project situations. For example, a grammatical/spelling mistake may have low priority in earlier project phases. But the priority becomes high when project is going live.

Tips to assign severity and priority

Keep below points in mind while assigning severity and priority to any defect.

  • Think from an end-user’s perspective and check how the defect would affect the user’s experience.
  • Understand the functionality well. Take help from PM, tech lead or test lead to know how the defect will impact the functionality.
  • Remember that severity level you assign to bug affects its priority. So always assign severity wisely.
  • Grasp the idea of severity and priority very well.

What practices do you follow while specifying severity and priority while testing? Share with us in comments.

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  1. Maanikamili

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