Classification of bugs
Bugs are classified into 4 main categories namely:
1. Critical
2. Major
3. Minor
4. Trivial
Whenever software testers log bugs in a bug tracing tool, they classify the bugs into any one of the categories mentioned above and depending on the classification of the bugs developers decide which bug needs to be fixed earlier and which one later. Let’s discuss each of these classifications in more detail:
Critical Bug
As the name suggests this type of bug hampers the usage of entire application. For example, if there is a bug in login functionality of the application and users are unable to log into the application then they could not perform any task in the application so until this critical bug is fixed no work could be performed and this thing turns into a loss to the business. Say you are trying to buy something from an Ecommerce application but you are unable to log into your account then you would move to another E-commerce application and this way the business of the earlier E-commerce website that has a critical bug suffers a lot.
Normally application is never released into production for end users to access it until all the critical bugs are found and fixed by the development team and testing team together.
Critical bugs are also called as showstoppers.
Major Bug
Major bugs do not affect the entire application but they do affect any of the major functionalities which are very important to the business. For example, although the user is able to log into an Ecommerce application i.e. there is no critical bug in the application but there is a major bug in the Cart functionality and users are unable to add anything to the cart so users are unable to proceed to buy things from this application that has a major bug.
Similar to Critical bugs, all major bugs needs to be fixed before releasing the application in production for end users to access it.
Major bugs are also called as High Level bugs.
Minor bug
Minor bugs do not affect the entire application or the complete functionality of any feature but they do impact any feature in a minor way. For example, in an E-commerce site videos of the product descriptions are not playing then it is a minor bug as the users are still able to see the pictures of the product, users are still able to read the product description etc., just the video of product description are not playing so if they are satisfied with the pictures and readable product description then they would proceed to buy the product even if the video product description is not working.
Generally applications are released into production with minor bugs as they do not hamper the business too much but the delay in the application release could hamper the business so it is better to release the application even if there are few minor bugs left to be fixed.
Minor bugs are also called as Medium Level bugs.
Trivial Bug
These bugs are of least importance and mostly they are related to the look and feel of the application. The best example of a trivial bug is a spelling mistake in any area of the application. Although there is a spelling mistake but the users are still able to understand the message of the application and would proceed with using the application.
Applications are always released even before all the trivial bugs are fixed by the development team.
Trivial bugs are also called as Low Level bugs or Cosmetic bugs.
So depending on the classification of bugs developers fix those bugs. If a tester logs 2 major bugs and 20 minor bugs then the developer needs to fix the 2 major bugs prior to the 20 minor bugs. Once the 2 major bugs are properly fixed, application could be released into production and side by side developers keep on fixing the minor issues and keep on releasing the new builds into production after minor bug fixes.
Software tester’s responsibility is to find at least all critical and major bugs at their end so that end users do not face any critical or major issue when they try to use the application at their end.