What is SDLC

Software Development and Management Models of Software Engineering

  • Plan
  • Design
  • Build
  • Test
  • Release
  • Monitor

Waterfall model

  • Requirements
  • Design
  • Implementation
  • Verification
  • Maintenance

Incremental build model

Spiral model

Agile model

The implementation of the agile model mainly includes SCRUM, XP (Extreme Programming), Crystal Methods, FDD (Feature Driven Development) and so on. Among them, SCRUM and XP are the most popular.

Popularity Diagram


Scrum is an approach for managing projects with more speed, flexibility and energy. Instead of relying on plans, documentation and meetings, you work with a dedicated team in short sprints towards your end result, using feedback from stakeholders along the way. Scrum is a flexible way of working, made for a rapidly changing world.

Scrum is widely used in software development, but is suitable for almost all projects and organizations.

Origin of Scrum:

The term ‘Scrum’ was first introduced by professors Hirotaka Takeuchi and Ikujiro Nonaka in 1986 in their article “The New New Product Development Game” at Harvard Business Review.

They borrowed the name ‘Scrum’ from the game of rugby, to stress the importance of teamwork to deal with a complex problem.

Scrum 3 Roles:

  • Product Owner
    • The key stakeholders with a vision who provides direction to the team for each sprint
  • Team
    • Five to nine professionals in various disciplines who are jointly responsible for the results
  • Scrum Master
    • A facilitator who focuses completely on the process then there are scrum lists

Scrum 3 Lists:

  • Product backlog
    • list your ambitions and express how you intend to achieve them
  • sprint backlog
    • the shopping list of products you want to produce in the next sprint
    • the definitions of done by the end of the sprint
  • Scrum board
    • all of the members tasks
    • task status
      • to do
      • busy
      • done

Scrum 4 Meetings:

  • Sprint planning
    • What exactly are we going to achieve during this sprint and who’s doing what
  • Standup
    • Everything going according to the plan and are we going to make it
  • Review
    • During which you deliver your results and receive feedback
  • Retrospective
    • You look back on the process and reflect what you can improve as a team for the next sprint

Definition of Ready (DoR) and Definition of Done (DoD):

  • DoR: It’s the standard for a requirement to be accepted by the team. It is considered that the requirement is ready and can flow into the research and development task queue. It is the standard for requirement admission.
  • DoD: The purpose of DoD is to give everyone a unified understanding of the “completion” standard and prevent misunderstandings. It can be divided into different dimensions to define.


Crystal Method




  • Scrum in under 5 minutes https://shawn-nie.github.io/2021/10/11/%E9%A1%B9%E7%9B%AE%E7%94%9F%E5%91%BD%E5%91%A8%E6%9C%9F%E7%9A%84%E7%8E%AF%E5%A2%83%E7%B1%BB%E5%9E%8B(Environment_Types)/ https://www.cnblogs.com/garrettwale/p/16256879.html