Validation

                                           

                                                                      Validation

Testing Approach:

Traditional testing approach:         Positive Testing (+ve).

   Show that the system:

*  D o e s what it should

 * G o a l : show working.

 * S u c c e s s : system works.

 * E a s y to write system cases

 * R e s u l t : faults left in.

Better Testing approach:                -ve Testing:

Show that the system:

* Doesn’t do what it shouldn’t.

* Does what is should

* Goal: find faults

* Success: system faults

 * Difficult to write test cases

 * Result: fever faults left in.

Most common defects :

• Incorrect functionality

• Incorrect data edits

•  Poor performance

•  Poor security

•  Incompatibility

•  Poor UI – User interface

•  Poor usability

Objectives of Testing :

1) To confirm whether the application is developed according to customer requirements or
not

2) Finding defects

3) To make sure all problems are resolved and close.

4) Finally testing is helpful to deliver a quality product and risk-free product to the
customer.

Software testing Principles:

Principles of testing:  Exhaustive principle is impossible.

Exhaustive Testing: If you test functionality with all possible valid inputs and invalid
inputs then it is called exhaustive testing.

*** Testing everything is called exhaustive testing.

• If you check the salary field 5000 , 5001,5002 .............50000 and 4999, 4998 etc is called exhaustive testing.

•  As exhaustive testing is impossible risk based testing is preferred (or) recommended..

Risk Based Testing:  Identifying the operations which most likely to cause failures and then
testing these functionalities on priority basis is called risk based testing.

Defect Clustering:  The small number of modules or functionality may contain more number of
defects. Concentrate more on testing these functionalities.

Pesticide Paradox: If prepared test cases are not finding defects, add/revise test cases to find
more defects.

 The prepared test cases are not helping to find defects then add or modify the test cases for better testing.

Testing shows presence of defects:1    We have to test a application with an intension of
showing defects. For this negative testing is the best approach.

Early Testing:  Testing should start as early as possible in the SDLC.

Testing is context dependent: We have to select or opt appropriate testing approach based
on the type of application we are testing.

Absence of Errors is a fallocy:  Finding and fixing defects. 100% bug free app is impossible.

***** (Fallocy = False statement)

Static Testing:  Verifying if we developing the right system or not is called static testing. It is
also called verification. T his static testing covers reviews and walk through.

Reviews : Examine any project related work or project related work is called reviews.

Types of Reviews:

1) Management Reviews

2) Technical Reviews

3) Code Reviews

4) Test case Reviews (formal, Informal)

Formal Reviews:  if any review is conducted with a prior plan and by following proper documentation and procedures are called formal reviews

Inspections and Audits are the best example of formal reviews.

Informal Reviews: if any review is conducted without following any procedures and documentation then reviews

Walk-through:  knowledge transfer sessions in the form of peer review

Objective of Reviews:  Reviews are helpful to determine

1) Defects in requirement.

2) Defects in design.

3) Deviations in coding standards.

4) To confirm if the prepared test cases are enough to validate a software

5) Reviews helpful improve the organization process.