Stop 01 · QA & Software Testing FoundationsTopics · 3/9

The Software Testing Life Cycle (STLC)

In short

Testing isn't one big 'test everything' moment at the end. It has its own stages, each with a clear output, so nothing gets forgotten.

A structured process — requirement analysis, test planning, test case design, environment setup, test execution, and closure — describing how testing work flows through a project.

The purple blob arranges question papers on desks in an empty exam hall.

Think of it like this

Running a board exam

First the board reads the syllabus, then plans the exam, sets the question paper, arranges halls and invigilators, conducts the exam and finally publishes results. Skip a step and chaos follows. The STLC is the same idea for testing.

Watch it happen

The six stages of the STLC

Requirements

Planning

Test design

Env setup

Execution

Closure

1/6Study the requirements to see what is testable and what is unclear. Questions go back to the product team.

The big ideas

What you need to know

Each stage has an output

Requirements give questions, planning gives a test plan, design gives test cases, closure gives a report.

Entry and exit criteria

Each stage has rules for when it can start and when it is finished, like 'build deployed' or 'no open critical bugs'.

STLC sits inside the SDLC

The SDLC is how software gets built. The STLC is the testing track running alongside it.

Agile shrinks it, not skips it

In a two-week sprint all six stages still happen, just in small, fast loops for each story.

Save yourself the pain

Common mistakes

Oops

Starting test execution with no plan or test cases because the deadline is close.

Do this instead

Even a one-page plan and a short checklist beat testing from memory. You will miss less and can show coverage.

Oops

Skipping closure because testing 'is done'.

Do this instead

A short closure note on what wasn't tested and which bugs remain open protects you and helps the next release.

Your mission

Run a mini STLC on a calculator app

~30 min

Quick check

In which STLC stage would you first spot that a requirement says 'fast response' without saying how fast?

Go deeper

1Sketch a real or hypothetical project through all STLC stages.
2Identify which stage is most commonly rushed under deadline pressure.
3Learn how STLC relates to, but is distinct from, the broader SDLC.