Software Testing Introduction and its Importance

    Software Testing Introduction :

• Software testing is a process used to identify the correctness, completeness, and quality of developed computer software. It includes a set of activities conducted with the intent of finding errors in software so that it could be corrected before the product is released to the end users. 
• In simple words, software testing is an activity to check whether the actual results match the expected results and to ensure that the software system is defect free.

     The purposes of testing are: 

• Quality assurance, Verification and Validation,
• To find the bugs before the product is released to customer.
• To improve the quality of the product 
• To evaluate that the product is according to requirements.

     Why is testing is important ?

• In April of 1999 ,a software bug caused the failure of a $1.2 billion military satellite launch, the costliest accident in history
• In may of 1996, a software bug caused the bank accounts of 823 customers of a major U.S. bank to be credited with 920 million US dollars

       Software Testing Life Cycle

Contrary to popular belief, Software Testing is not a just a single activity. It consists of series of activities carried out methodologically to help certify your software product. These activities (stages) constitute the Software Testing Life Cycle (STLC).

          The different stages in Software Test Life Cycle - 

Each of these stages have a definite Entry and Exit criteria  , Activities & Deliverables associated with it.

In an Ideal world you will not enter the next stage until the exit criteria for the previous stage is met. But practically this is not always possible. So for this tutorial , we will focus of activities and deliverables for the different stages in STLC.

 WHO AND WHEN TO START TESTING

Who does testing: Following professionals are involved in testing of a system within their respective  capacities:

• Software Tester
• Software Developer
• Project Lead/Manager
• End User

    When to Start Testing ?

Testing is done in different forms at every phase of SDLC like during Requirement gathering phase,  the analysis and verifications of requirements are also considered testing.

     Advantage:-

• Manual testing can be use in both small and big project.
• We can easily reduce and add our test case according to project movement.
• Easy to learn for new people who enters in manual testing.
• Manual  testing is more reliable then automated (in many cases automated test not cover all cases) .

    Disadvantage:-

• GUI object size difference and color combination etc is not easy to find out in manual testing.
• Actual load and performance is not possible to cover in manual testing for large number of users.