Software Development Lifecycles

The main stages of systems development

The systems development life cycle is a framework describing a process for understanding, planning, building, testing and deploying an information system. Generally, the main stages consist of;

  1. Feasibility Study
  2. Requirements Engineering
  3. Design
  4. Development (Programming)
  5. Testing
  6. Implementation

System development can either follow a linear or evolutionary approach. Within the two approaches are five basic system development lifecycles;

  • Waterfall
  • ‘V’ Model
  • Incremental
  • Iterative
  • Spiral

At my workplace

My workplace follows the waterfall lifecycle. The waterfall lifecycle follows the linear approach.

Linear approaches follow the SLDC stages in a defined order. Each step must be completed, understood and agreed before the next step can be started.

The principles behind Waterfall  lifecycle is that each step must be completed before the next. So the feasibility study must be completed before the requirements engineering can be started, and the requirements engineering must be completed before he design can be stared and so on.

The route taken at my workplace is as follows;

  1. A proposal is brought forward and it is routed to the sponsor
  2.  A feasibility study is carried out to see whether it would fit in the roadmap, if so it would be placed on the roadmap
  3. Shape and plan the project
  4. Design
  5. Build
  6. Validation
  7. Testing
  8. Deliver (Service Acceptance and Go live)
  9. End of project Review – Reviews lessons learned and ensures the benefits plan is in place

Benefits and Weaknesses of the linear approach and the waterfall cycle

Benefits

  • Good for breaking down problems into distinct stages, each with a clear purpose
    • Good for developing systems where the requirements and likely solution are well understood and are unlikely to change
  • This model is simple and easy to understand and use.
  • It is easy to manage due to the rigidity of the model – each phase has specific deliverable and a review process.

Weaknesses

  • Doesn’t cope well with changing requirements
  • If the project is stopped early there is little of business value to show for cost
  • Poor estimation can severely impact project cost and schedule
  • Depends greatly on each stage being done properly, as it is hard or impossible to go back and change it later

Roles

  • Sponsor – Sponsors for the project and business case. The project executive.
    • Project Manager – Manages the project.
    • Technical Coordinator – Accountable for the technical solution design. Lead architect, accountable for compliance with design authority and associated standards.
    •  Improvement Champion – Champions and delivers business change. Supports the business sponsor. Fully engaged in the business from consultation to implementation.
      • Team Leader – Leads the delivery team.
        • Business Ambassador – Fully engaged in the project from requirements through to live operation
        • Business Adviser – Advises and contributes on subject matter topics
        • Business  Analyst – Develop and design business process.
        • Business Tests – Tests the solution, making sure that it works as desired from the perspective of those who will use the solution.
        • Solution Adviser – Advises and contributes on subject matter topics and specialist domain design
        • Solution Developer – Develops and designs the solution under the direction of the technical and business readiness
        • Solution Tester – Tests the delivered solution based on the technical, functional and non-functional requirements
        • Improvement Facilitator – Provides neutral facilitation
      • Service Manager(s) – Run and improve the delivered solution

Business Roles

Technical Roles

Project Roles

https://www.tutorialspoint.com/sdlc/sdlc_waterfall_model.htm

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