Chapter 1 - Introduction to SDLC

What is the Software Development Lifecycle (SDLC)?

The Software Development Life Cycle (SDLC) is a structured process used by software developers to build high-quality software applications and manage projects efficiently. It divides software development and maintenance into distinct phases, providing a clear roadmap for teams to follow.

A circular loop outlining the 6 common phases of the Software Development Cycle

Source: K21Academy

SDLC Phases

1. Planning

Define the project scope, technical and business needs, and any constraints.

2. Design

Analyze the requirements to create practical solutions to solve the defined problems.

3. Implement

Developers write code to achieve the project’s design goals.

4. Test

Use automated and manual testing methods to identify bugs or errors in the software.

5. Deploy

Release the completed software into a production environment for user access.

6. Maintain

Continuously update and support the software to address issues and improvements.


Benefits of SDLC

  • Structured project management aligned to product goals
  • Improved communication and collaboration between teams
  • Built-in risk mitigation throughout each phase
  • Reduces human error through rigorous testing
  • Enables faster, more secure, and reliable software delivery

Common SDLC Methodologies

Methodology Description Use Cases
Waterfall A linear approach where each phase must be completed before moving to the next. Ideal for small, well-defined projects with fixed requirements.
Iterative Builds software in small parts, allowing feedback and revisions after each iteration. Useful when early versions are expected to evolve based on user feedback.
Agile A flexible, iterative approach that emphasizes collaboration, customer feedback, and frequent updates. Best for dynamic, fast-paced projects with evolving requirements.
Scrum A subset of Agile, focusing on time-boxed iterations called sprints and daily stand-up meetings. Great for product-based development with frequent releases and tight deadlines.

🧠 Knowledge Check

Answer the questions below to test your knowledge!

Q1: What is the primary purpose of the Software Development Life Cycle (SDLC)?

Q2: Which of the following is NOT one of the phases in the traditional SDLC?

Q3: True or False: The Maintain phase in SDLC focuses on releasing software into production.

Q4: What is a key benefit of following a structured SDLC process?

Q5: Which SDLC methodology is best suited for projects with fixed, well-defined requirements?