What is Defect (Bug) Life Cycle in Software Testing? Complete Guide with Diagram and Stages

Understanding the Concept

The Defect Life Cycle is also known as the Bug Life Cycle.
Defect life cycle is a process in which defect goes through different stages in its entire life. It starts when a defect is found and ends when a defect is closed, after ensuring it's not reproduced. Defect life cycle is related to the bug found during testing.
 

Why Defect Life Cycle is Crucial in Software Testing

The Defect Life Cycle is extremely important in software testing because it helps in:

• Maintaining software quality
• Tracking progress
• Ensuring accountability regarding who is assigned to a specific bug
• Ensuring unresolved bugs do not make it to production

 

Stages of the Defect Life Cycle in Software Testing

 

1. New
   During the testing phase, if a tester or the testing team discovers a new bug, they log it as 'New' in the defect tracking system.
   Remember, bugs of this type - when logged for the first time automatically fall into the 'New' state.
    
2. Assigned
   Once a bug has been logged and assigned to the appropriate developer within the development team, its status changes to the "Assigned" stage.
    
3. Open or Active or In Progress
   Now, in this state, the developer begins analyzing the bug, and the stage transitions from "Assigned" to "Open."
   Developers now have three options available to them, in addition to simply resolving the issue:
    
   1. Deferred - If the developer determines that the bug is not of high priority, or that it does not pertain to the current release and can be resolve in next release, they set the status to "Deferred".
      The "Deferred" status is also referred to as the "Postponed state".
       
   2. Duplicate - If the same bug is reported twice or if it is essentially the same issue or concept, such that resolving one instance would effectively eliminate the other or if the bug had been raised previously and subsequently closed, then the developer marks it as "Duplicate" stage.
       
   3. Rejected - If the developer determines that this is not an genuine bug, or if the bug cannot be reproduced upon analysis, they set its status to "Rejected".
      So, the developer has options to reject are Duplicate Defect, NOT a Defect, or Non-Reproducible.
       
4. Fixed
   If none of these conditions are met, then the developer needs to resolve the bug.
   After making the necessary changes and bug fixes in the code, the developer hands it over to the testing team and sets the status to "Fixed".
    
5. Re-testing
   This stage is also referred to as 'Pending Request'.
   The testing team will now begin retesting this bug and mark the stage as "Re-testing". And the testing team tests whether the bug has been truly resolved or not.
    
   • Re-open - The tester performs a test, if a bug is detected and has not been resolved, they reopen it. This stage is marked as "Re-open" and the same defect lifecycle resumes, though the "New" stage is skipped in this cycle.
      
6. Verified
   It is also referred to as 'Ready to Close'.
   In this stage, the tester checks whether the bug has been fixed or not, and whether the bug fix has affected other models(Regression Testing).
   If everything good, the tester marks this stage as "Verified".
    
7. Closed
   This state means that the bug is fixed, tested and approved.
   If the bug passes the "Re-testing" and "Verified" stages, then the issue of this bug can now be closed and this stage is marked as "Closed".

 

Popular Defect Tracking Tools for Software Testing

Defect tracking tools also known as Bug Tracking Tools assist testing teams in efficiently identifying and managing defects throughout the entire development process.
Utilizing the right tool enhances product quality, improves product quality, team collaboration and project delivery timelines.

Listed below are some of the most popular tools currently in use.

1. JIRA
   License: Open-source / Paid
   This is a very popular bug-tracking tool and is used in Agile project management.
   
   Pros
   • Highly customizable workflows
   • Strong reporting & dashboards
   • Great integrations (Jenkins, Bitbucket)
      
   Cons
   • Can be complex for beginners
   • Expensive for large teams
      
2. Bugzilla
   License: Open-source
   This tool is highly reliable for small and medium-sized teams developed by Mozilla.
   
   Pros
   • Free and stable
   • Advanced search & reporting
   
   Cons
   • Oudated UI
   • Setup not be easily
      
3. MantisBT
   License: Open-source
   A lightweight web based bug tracking system.
   
   Pros
   • Easy to set up
   • Lightweight and fast
      
   Cons
   • Limited advanced features
   • Basic interface

There are many other Bug Tracking Tools available such as Redmine, YouTrack, Azure DevOps (Boards), Trello, Zoho BugTracker, GitHub, and GitLab Issues each with its own set of pros and cons, moreover most of them are paid or commercial license.
 

Advantages of Defect Life Cycle in Software Testing

The Defect Life Cycle offers numerous benefits to the testing process some of these are listed below.

1. Clear Tracking of Defects - It provides a structured framework for tracking defects ensuring that nothing is missed or ignored.
2. Improved Communication - Team collaboration among testers, developers and managers is highly beneficial, as it provides significant assistance and ensures that the status of every defect is known.
3. Better Prioritization of Defects - This helps the team identify which defects are critical and which are not and determine which ones need to be resolved first.
4. Accountability in Team Members - Every defect is assigned to a specific team member, ensuring that responsibilities remain clear.
5. Improved Project Management - The manager can effectively monitor and understand the project specifically, how many bugs are open, how many have been fixed and how many remain pending.
   Every defect follows a specific stage, so issues are resolved quickly and efficiently.

 

Disadvantages of Defect Life Cycle in Software Testing

While there are so many benefits, the Bug Life Cycle also has a few limitations.

1. Time Consuming Process - If the defect lifecycle is not managed properly, unneccessary delays occur at every stage, slowing down the process.
2. Complex Workflow - The numerous stages make the process complicated for beginners.
3. Dependency on Team Communication - If developers and testers do not communicate effectively with each other, defect resolution may be delayed or subject to misunderstandings.
4. Not Suitable for Very Small Projects - For very small projects, the defect life cycle is extremely time consuming and causes unnecessary delays.