Engineering & SDLC
This revision lesson covers the System Development Life Cycle (SDLC) — the structured process for planning, creating, testing, and deploying information systems. You'll review development frameworks, prototyping, and hardware requirements.
Learning Objectives
- 11.2.2.3 Describe the characteristics of a development framework
- 11.2.2.5 Discuss the use of prototypes based on a specific example
- 11.2.2.6 Develop a prototype for a new system
- 11.2.2.7 Define minimum requirements for hardware when implementing solutions
Key Concepts Review
SDLC Models
| Model | How It Works | Best For |
|---|---|---|
| Waterfall | Linear, sequential phases — each phase completed before the next begins | Well-defined requirements, small projects |
| Iterative | Repeated cycles of development — each iteration adds new features | Large projects where requirements evolve |
| Spiral | Combines iterative with risk analysis at each loop | High-risk, large-scale projects |
| Agile | Short sprints (2–4 weeks), continuous feedback, flexible to changes | Dynamic requirements, team collaboration |
| RAD | Rapid Application Development — heavy use of prototyping and user feedback | Time-critical projects |
Prototyping
What Is a Prototype?
A prototype is an early, simplified version of a system used to demonstrate concepts and gather user feedback. It can be a paper sketch, a clickable wireframe, or a working model with limited functionality. Prototyping reduces risk by catching design flaws early.
| Advantages | Disadvantages |
|---|---|
| User sees a working model early | Can lead to scope creep |
| Identifies problems before full build | Users may think the prototype is the final product |
| Reduces development risk and cost | Time spent on throwaway prototypes |
Hardware Requirements
Defining Minimum Hardware
When implementing a solution, you must specify: CPU speed, RAM, storage, operating system, network requirements, and any peripherals (printer, scanner). These ensure the system runs reliably for all users.
Revision Tasks
Name 4 SDLC models and state one key characteristic of each.
Explain why prototyping is useful and give an example of when it would be appropriate.
Create a list of minimum hardware requirements for a school library management system.
Compare the Waterfall model and Agile. Which would you choose for a mobile app startup and why?
Self-Check Quiz
Q1: Which SDLC model is best when requirements are unclear and likely to change?
Q2: What is the main purpose of a prototype?
Q3: Name 3 things you should include when defining hardware requirements.