SDLC: Overview and Phases

Lesson objectives

By the end of the week, learners should be able to:

1. Define the software development life cycle and state its phases.
2. Name the eight phases in order.
3. Explain the purpose of each phase briefly.
4. Compare waterfall and agile models on flexibility.
5. Judge which model suits a small team project.

Key vocabulary

• Software development life cycle: the ordered stages of building software.
• Phase: one stage in the development process.
• Waterfall: a linear model moving strictly through stages once.
• Agile: an iterative model repeating cycles of planning, building and testing.
• Verification: confirming the product meets requirements.
• Validation: confirming the product meets user needs.
• Documentation: written records describing processes and decisions.
• Requirements gathering: collecting what the software must do.
• Design: specifying the technical architecture.
• Implementation: writing the actual code.
• Testing: verifying the product works correctly.
• Deployment: releasing the product to users.
• Maintenance: fixing defects and adding features over time.

Common misconceptions

• "Waterfall never revisits earlier phases." Waterfall revisits earlier phases on major defects.
• "Agile is chaotic development." Agile has disciplined iteration cycles inside loops.
• "Testing happens only at the end." Testing runs throughout the life cycle continuously.

Teacher activities

1. Starter: display a waterfall chart and an agile chart side by side and ask which suits a school assignment.
2. Define the SDLC and state the eight phases in order.
3. Explain the purpose of each phase briefly on the board.
4. Compare waterfall and agile on flexibility and documentation.
5. Explain why agile suits iterative projects better than waterfall.
6. Close with the model-suit choice task and exit question.

Student activities

1. Choose the starter item and explain the preference reason.
2. Define the SDLC in their own words and list the eight phases in order.
3. State the purpose of each phase in one sentence each.
4. Compare waterfall and agile on flexibility and documentation.
5. Judge which model suits a small team project and justify it.
6. Answer the exit question in one sentence about waterfall revisits.

Practical / learning evidence

An eight-phase waterfall chart with purposes, a waterfall versus agile comparison and a small-team justification paragraph. Submit all three for marking.

Resources and preparation

Printed chart templates, blank comparison sheets and sample project scenarios. Offline route: paper versions, no device needed. Display diagrams carefully and avoid touching any hardware used in demos.

Assessment for learning

Inspect the eight-phase chart for all eight phases in order and sensible purposes. Mark the waterfall versus agile comparison for equal criteria. Check the small-team justification for a defensible rationale. Flag any learner who claims waterfall never revisits earlier phases.

Inclusion and homework

Provide the chart prefilled for the first six phases and allow oral completion of the rest. Allow extra time on the comparison. Extend confident learners with ten more phases and a ten-scenario comparison. Homework: describe one real application built with the waterfall model in one paragraph.