"Overview of Software Development Life Cycle Models"

Software Development Life Cycle

1. Waterfall

• Phases: DESIGN, ANALYSIS, BUILD, TEST, DEPLOY
• Key Points:
  • Linear sequential model.
  • Each phase depends on the output of the previous phase.
  • Easy to manage due to its rigid structure. However, not flexible in handling changes.

2. Spiral

• Phases: Evaluate, Test, Risk Analysis, Design, Build, Verify, Plan Next Iteration, Develop, Identify Risks
• Key Points:
  • Combines iterative development with systematic aspects of the waterfall model.
  • Focus on risk analysis and minimization.
  • Allows for incremental releases of the product, or incremental refinement through each iteration around the spiral.

3. Agile

• Phases: SPRINT 1, SPRINT 2, SPRINT 3, etc.
• Key Points:
  • Promotes collaboration, customer feedback, and small, rapid releases.
  • Projects are divided into small sprints, usually lasting 1-4 weeks.
  • Offers flexibility and encourages continuous improvement.

4. Iterative

• Phases: Iteration 1, Requirement, Analysis, Design, Testing, Implementation, Review, Iteration 2, Iteration 3, Deployment, Maintenance
• Key Points:
  • Involves developing a system in repeated cycles (iterations).
  • Each iteration delivers a part of the software, which is reviewed and improved in the next iteration.
  • Best for projects with unclear or dynamic requirements.

5. V-Model (Validation and Verification Model)

• Phases:
  • Developer’s Life Cycle: Business Req. Specification, System Req. Specification, High Level Design, Low-Level Design, Coding
  • Tester’s Life Cycle: Acceptance Testing, System Integration Testing, Component Testing, Unit Testing
• Key Points:
  • Extension of the waterfall model, mapping testing phases to each development stage.
  • Ensures verification and validation activities are performed simultaneously.
  • Can be rigid; does not handle changes easily.

6. Incremental

• Phases: Increment-1, Increment-2, Increment-3
  • Each increment follows this cycle: Analysis, Design, Code, Test
• Key Points:
  • Divides the system into smaller segments (increments).
  • Each segment is developed and delivered separately.
  • Useful for iterative enhancements and additions.

7. Big Bang

• Phases:
  • Time, Resources, Efforts -> BIG BANG -> SOFTWARE PRODUCT
• Key Points:
  • Involves little to no planning.
  • All resources are invested in the development, leading to a single release.
  • High risk, as fundamental issues can't be identified early.
  • Suitable for small projects with unknown requirements.

8. RAD (Rapid Application Development)

• Phases: Analysis & Quick Design, Prototype Cycles (Design, Refine, Demonstrate), Testing, Deployment
• Key Points:
  • Focuses on rapid prototyping and quick feedback over strict planning.
  • Involves stakeholder interaction and refining prototypes.
  • Accelerates the development process, delivering components more quickly.

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