Development Life Cycle

The Four Stages at a Glance

• Analysis = figuring out exactly what problem needs solving, using abstraction to strip away irrelevant detail and focus on core functionality and requirements.
• A requirements document is produced during analysis — it lists each requirement with a description and a success criteria so everyone knows when it's "done."
• Design = turning the understood problem into a blueprint, shown using structure diagrams, flowcharts, or pseudocode.
• Coding = writing the actual program in modules, with iterative testing happening constantly as each module is built and re-tested.
• Testing (the final stage) = running the whole finished program repeatedly with varied test data to check it meets requirements and handles invalid input correctly.

What actually happens here?

Before anyone writes a single line of code, the team has to be brutally clear about what problem they're actually solving. This sounds obvious, but it's the stage most beginner programmers skip — and it's exactly why their programs end up solving the wrong problem, or missing half the features the client actually wanted.

The analysis stage is defined as: precisely understanding the problem the program is intended to solve. Not "roughly understanding" — . That word matters in exam answers.

Core Functionality

Using abstraction helps identify the fundamental components of what the program is actually going to solve — i.e. the essential jobs the program must do, stripped of extra detail.

Two things need to be nailed down before any coding starts:

• clearly understood by everyone working on it
• overall goal constraints platform

Requirements Document