Software Testing Life Cycle (STLC)

Software Testing Life Cycle (STLC) defines the steps/ stages/ phases in testing of software. However, there is no fixed standard STLC in the world and it basically varies as per the following:

Software Development Life Cycle
Whims of the Management

Nevertheless, Software Testing Life Cycle, in general, comprises of the following phases:

Phase	Activity	Deliverables	Necessity
Requirements/ Design Review	You review the software requirements/ design (Well, if they exist.)	‘Review Defect’ Reports	Curiosity
Test Planning	Once you have gathered a general idea of what needs to be tested, you ‘plan’ for the tests.	Test Plan Test Estimation Test Schedule	Farsightedness
Test Designing	You design/ detail your tests on the basis of detailed requirements/design of the software (sometimes, on the basis of your imagination).	Test Cases / Test Scripts /Test Data Requirements Traceability Matrix	Creativity
Test Environment Setup	You setup the test environment (server/ client/ network, etc) with the goal of replicating the end-users’ environment.	Test Environment	Rich company
Test Execution	You execute your Test Cases/ Scripts in the Test Environment to see whether they pass.	Test Results (Incremental) Defect Reports	Patience
Test Reporting	You prepare various reports for various stakeholders.	Test Results (Final) Test/ Defect Metrics Test Closure Report Who Worked Late & on Weekends (WWLW) Report [Depending on how fussy your Management is]	Diplomacy

Note that the STLC phases mentioned above do not necessarily have to be in the order listed; some phases can sometimes run in parallel (For instance, Test Designing and Test Execution). And, in extreme cases, the phases might also be reversed (For instance, when there is Cursing prior to Testing).

Interestingly, no matter how well-defined a Software Testing Life Cycle you have in your project or organization, there are chances that you will invariably witness the following widely-popular cycle:

Testing
Cursing

In this type of STLC, you skip phases like design review, test planning, etc – in the hope that the skipping will save you some time and/or cost [But, it never does].