Negative Testing in Software testing

Definition: Negative testing is a testing process where validation is done by passing Invalid, Incorrect and False-Positive Input test data & also with scenarios which have a negative impact on business functionality.

The survey shows that count of issue related to negative testing is much more than count of issues of positive testing this shows the importance of negative testing towards user experience. Negative testing ensures application is fault proof.

Some of Negative scenarios

 1>  Negative  scenarios

a.    Null (if mandatory)    : Invalid test data

b.    Less than minimum   : Incorrect length test data

c.    More than maximum  : Incorrect length test data

d.    Other than defined data type : Invalid test data

e.    Duplication check

f.     False Positive test

g.    Less/More than stock/balance quantity

h.    Less/More than available amount

i.      Disaster recovery -  Roll back

Listed Negative testing scenarios also included in Smoke test as passing negative testing scenarios gives extra confidence on Quality of application & delivery.

Negative scenarios are identified as per type of application, User who will be using application, rollback scenarios, 

By knowing type of application & users who will be using it, identification of negative scenarios becomes much more effective for example: if an application would be used by Layman user then all possible negative scenarios should be listed whereas for application which will be used by trained executive would not require all negative scenarios.

Sometimes it become difficult to take decision, should we resolve all reported negative issues in such cases management may sort as per priority (must have), good to have & known issue

The following are some of the benefits of negative testing:

• It benefits in measuring the functional transparency.
• It benefits identifying the risk conditions under which the system crashes.
• It assists in preventing/detecting serious flaws in the exception handling mechanisms.
• Ensures that the function/application accept the data correctly and handles invalid data in the right way.

Positive testing is done to ensure that the happy business functionality is achieved, negative testing ensures that there is no fault & user experience is good. Negative testing helps to find more defect thus including negative scenarios in test case would have more defect prevention approach.

About Author:

Vinayak Jadhav is a consultant in Systems Plus Pvt. Ltd. Within Systems Plus, he actively contributes to the areas of Technology and Information Security. He can be contacted at:  vinayak.j@spluspl.com