SDLC for App Development - johnverz22/appdev-lessons GitHub Wiki

The Software Development Life Cycle (SDLC) is a structured process used for developing software applications. It provides a systematic way to plan, create, test, and deploy software, ensuring high quality and reliability. For beginners, here’s a detailed explanation of the SDLC phases, simplified for better understanding:

SDLC

1. Planning

  • Purpose: Determine the goal of the software project and its feasibility.
  • Activities:
    • Identify the problem or need for the software.
    • Define objectives: What the software should achieve.
    • Perform feasibility studies: Check if the project is economically, technically, and operationally viable.
    • Plan resources, time, and cost estimates.
  • Outcome: A project plan that acts as a roadmap for the entire process.

2. Requirement Analysis

  • Purpose: Understand what the users need the software to do.
  • Activities:
    • Gather requirements through interviews, surveys, and user meetings.
    • Document functional requirements (what the software should do) and non-functional requirements (e.g., performance, security).
    • Create a Software Requirements Specification (SRS) document.
  • Outcome: Clear, detailed requirements that guide the next steps.

3. Design

  • Purpose: Develop a blueprint for the software system.
  • Activities:
    • Define the system architecture (how components interact).
    • Choose technologies, tools, and programming languages.
    • Create diagrams such as flowcharts, ERDs (Entity-Relationship Diagrams), or UML (Unified Modeling Language) diagrams.
    • Design user interfaces (UI) and user experiences (UX).
  • Outcome: Design documents, prototypes, or mockups.

4. Implementation (Coding)

  • Purpose: Build the actual software based on the design.
  • Activities:
    • Write code according to design specifications.
    • Divide tasks among developers if working in teams.
    • Follow coding standards and use version control (e.g., Git).
  • Outcome: The first version of the software, also known as the "build."

5. Testing

  • Purpose: Ensure the software works correctly and meets requirements.
  • Activities:
    • Perform different types of testing, such as:
      • Unit Testing: Testing individual components or modules.
      • Integration Testing: Ensuring components work together.
      • System Testing: Checking the entire system's functionality.
      • User Acceptance Testing (UAT): Getting feedback from end-users.
    • Identify and fix bugs or errors.
  • Outcome: A stable, bug-free product ready for deployment.

6. Deployment

  • Purpose: Deliver the software to users.
  • Activities:
    • Release the software to production environments.
    • Provide installation guides or set up the system for users.
    • Offer training or documentation for end-users if needed.
    • Monitor the system after release for any issues.
  • Outcome: The software is live and available to users.

7. Maintenance

  • Purpose: Keep the software updated and functional over time.
  • Activities:
    • Fix any new bugs or issues reported by users.
    • Add new features or enhancements based on feedback.
    • Ensure the software remains compatible with new technologies.
    • Perform regular updates for security and performance.
  • Outcome: A long-lasting and up-to-date software product.

Benefits of Using SDLC

  • Clarity and Organization: Each phase has a clear objective.
  • Risk Management: Early detection of issues reduces risks.
  • Cost and Time Efficiency: Proper planning minimizes waste.
  • High Quality: Regular testing ensures reliability.

SDLC Models

Beginners should also know there are different models for implementing the SDLC. These include:

  1. Waterfall Model: Linear and sequential, moving step-by-step through phases.
  2. Agile Model: Iterative and flexible, focusing on small, incremental changes.
  3. Spiral Model: Combines iterative development with risk management.
  4. V-Model: Emphasizes verification and validation at each stage.

Tips for Beginners

  • Think of SDLC as a story: You plan (idea), write (code), and edit (test) your project before publishing (deploy) it.
  • Always document your work in each phase.
  • Focus on teamwork, especially during planning, design, and testing.
  • Learn basic tools for coding (e.g., IDEs, Git), testing (e.g., Selenium), and deployment (e.g., Docker).