Show understanding of the purpose of a development life cycle

12.1 Program Development Life Cycle 🚀

The Program Development Life Cycle (PDLC) is like a recipe that guides you from the first idea to the final, polished software. It ensures that every step is planned, checked, and improved, so the end product is reliable, efficient, and meets user needs. Think of it as building a LEGO set: you need a plan, the right pieces, assembly, testing, and sometimes a few tweaks after you finish.

Why Do We Need a Life Cycle? 🛠️

- **Reduces surprises**: By defining requirements early, you avoid costly changes later. - **Improves quality**: Regular testing catches bugs before they become big problems. - **Facilitates teamwork**: Everyone knows what to do and when. - **Supports maintenance**: Clear documentation makes future updates easier.

The Five Main Phases

1. Requirements – Gather what the user wants.
   • Interview stakeholders (like asking a friend what they want in a game).
   • Document functional and non‑functional needs.
2. Design – Plan the structure.
   • Create flowcharts, UML diagrams, or simple sketches.
   • Decide on algorithms and data structures.
3. Implementation – Write the code.
   • Follow coding standards (like a consistent spelling rule).
   • Use version control to keep track of changes.
4. Testing – Verify the program works.
   • Unit tests for small parts, integration tests for the whole system.
   • Use test cases that cover edge conditions (e.g., $x = 0$ or $x = -1$).
5. Maintenance – Keep the software running.
   • Fix bugs reported by users.
   • Update features or adapt to new hardware.

Analogy: Building a LEGO House 🏠

• Requirements – Decide the house’s purpose (e.g., a bedroom, a kitchen).
• Design – Sketch the floor plan and choose colors.
• Implementation – Assemble the bricks following the plan.
• Testing – Check that doors open and windows stay closed.
• Maintenance – Replace a broken brick or repaint.

Exam Tip: Remember the Cycle Flow 🔄

When answering questions, start by listing the five phases in order. Then, for each phase, give 1–2 key activities and explain why they matter. Use the phrase “PDLC” to show you know the acronym.

PDLC Summary Table