What is Defect?
Deviation for requirement specification is called as Defect.

Difference between Defect, Bug, Error and Failure?

Deviation for requirement specification
Bug is an informal name given to defect.
Mistaken done in program resulting unable to compile or run.
Defect causes Failure. One defect can cause multiple failures.

Why Defect is rejected?

Case 1: Misunderstanding of requirement - if a feature is misunderstood as a bug or sometimes Dev may give justiifcation saying its a feature not a bug.

Case 2: Referring to an old requirement - if the feature is removed from the template and the tester is testing the module and raises a defect.

Case 3: Extra implemetation - extra feature is developed which is not there in the requirement specification.

Duplicate Bug:

For example Tester 1 and Tester 2 are testing some common application and find a defect with the application. Both the testers raise the defect for the same. If tester 1 has raised the defect first and tester 2 raises the defect second, then tester 2 defect become duplicate bug.

Case 1: Commom Features - Common features are tested among the testers.

Case 2: the above example

Case 3: Known bug - if tester1 has already raised a defect for the application1 and starts testing application2. Tester2 starts testing application1 and finds the same issue in app2 and raises a defects then this defect becomes duplicate bug.

Why a defect/bug cannot be fixed?

Case 1: Technology only is not supporting, there is no solution for fixing this bug in that programming lang.

Case 2: Its a minor bug and the technology itself is not supporting for fixing this defect.

Case 3: Cost of fixing the bug is more than cost of the bug.

Case 4: if the defect is present in the root of the product.
Eg: if youfind a defect in the root of java, then fixing that bug will affect the other features in java.

Defect is not able to Reproduce?


Case 1: Improper Defect Report - steps to reproduce the defect is not mentioned correctly

Case 2: Data Mismatch - login as abc and click on inbox page, results in blank page. So log a defect and the dev team will login as xyz and click on inbox page, pages opens. Here mismatch of account id)

Case 3: Inconsistent Defects  - Reproducing the defect is inconsistent.

Case 4: Platform Mismatch - OS / Browser mismatch


Why a defect is postponed/deferred?

Case 1:If the defect is minor one.

Case 2: Dev team accept the defects, but takes time in confirmation fromcustomer if this is valid or invalid.


Why a bug is RFE(Request for Enchancement)

When you find a defect and the feature is nto available in the requirement, but developer accepts the bug, so that can be RFE.  Getcutomer approval and fix the RFE.