System Development Life Cycle Models - Chapter 2

Chapter 2: System Development Life Cycle Models

• This chapter focuses on System Development Life Cycle (SDLC) models
• Learning objectives include identifying traditional SDLC models, explaining differences between models, and listing SDLC stages.

2.1 Traditional Life Cycle Models

• Traditional Life Cycle Models are structured methods used in software and system engineering
• They follow a linear or sequential process with clearly defined stages
• Examples include:
  • Waterfall Model: A linear approach; each phase (Requirements, Design, Implementation, Testing, Deployment, and Maintenance) must be completed before moving to the next.
  • V-Model (Validation and Verification): Extends the Waterfall model by emphasizing testing and verification at each development stage.
  • Incremental Model: Divides the project into smaller segments; allows portions to be developed and delivered incrementally
  • Iterative Model: Focuses on refining and revisiting processes; repeated cycles improve the system at each iteration
  • Prototype Model: Involves creating an initial prototype to gather user feedback and refine requirements

2.1 Traditional Life Cycle Models (Continued)

• A diagram illustrating the Waterfall model shows the sequential flow from Requirement Analysis to System Design, Implementation, Testing, Deployment, and Maintenance.

• A diagram illustrating the V-Model shows the verification and validation phases at each stage of development in a V-shape.

• A diagram illustrating the Incremental model shows the project divided into smaller segments, delivered incrementally. Steps in the cycle are repeated for each iteration.

• A diagram illustrating the Iterative model shows repeated cycles focusing on refining and improving the system at each iteration.

• A diagram illustrating the Prototype model shows the steps for requirement gathering and building the prototype.

2.2 Modern Life Cycle Models

• Modern Life Cycle Models are contemporary approaches to software development
• They emphasize flexibility, adaptability, iterative progress to account for dynamic business needs and evolving technologies
• These models contrast with traditional ones via continuous improvement, collaboration, and faster delivery
• Examples include:
  • Rapid Application Development (RAD): Emphasizes speed, flexibility, and iterative development to quickly deliver a working product. Minimizes planning and maximizes user involvement
  • Agile Model: A flexible and iterative approach that promotes collaboration, customer feedback, and small, rapid releases
  • Scrum: A subset of Agile focused on short development cycles (sprints) with defined roles like Scrum Master and Product Owner
  • Kanban: A lean methodology emphasizing visual workflows and limiting work-in-progress to improve efficiency
  • DevOps: Combines development and operations to enhance collaboration, automate processes, and enable continuous delivery and integration
  • Spiral Model: Combines iterative development with a risk-driven approach, repeatedly passing through planning, design, build, and testing phases.

2.3 Overview SDLC Stages

• Traditional SDLC methodology used to develop, maintain, and replace information systems
• Consists of five phases:
  • Planning and Selection
  • Analysis
  • Design
  • Implementation
  • Maintenance
• Phases are not necessarily sequential
• Each phase has a specific outcome and deliverable
• Individual companies may adapt lifecycles

2.3 Overview SDLC Stages (Continued)

• Planning: Determines an information system's total needs and prioritizes them
• Analysis: Studies current procedures and information systems, determines requirements, generates design options and recommends the best alternative.
• Design: Describes the recommended solution, creating logical and physical specifications. Logical design defines all functional features; physical design specifies the technology-specific details.
• Implementation: Codes, tests, installs and supports the new system within the organization.
• Maintenance: Monitors the information system; makes changes to resolve user issues reflecting evolving business conditions to maintain running and useful systems. Programmer adjustments reflect user needs and business changes.

Additional Information

• A table outlining the products, outputs, and deliverables for each SDLC phase are provided
• Diagrams illustrate the components of the Waterfall, V-Model, Incremental, Iterative, and Prototype models, along with the Evolutionary and systems development lifecycle models.