System Development Life Cycle Models - CSC 1403

Chapter 2: System Development Life Cycle Models

• System Analysis and Design Fundamentals (CSC 1403)

Learning Objectives

• Identify the traditional models of SDLC
• Explain the differences of systems life cycle models used in system development
• List all the stages of SDLC

2.1 Traditional Life Cycle Models

• The term "Traditional Life Cycle Models" refers to structured approaches for software development and system engineering.
• These models are linear or sequential, frequently having clearly defined stages.
• They are used to plan, design, implement, test, and maintain projects.

2.1.1 Examples of Traditional Life Cycle Models

• Waterfall Model: A linear approach where 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 every development stage.
• Incremental Model: Divides the project into smaller segments for incremental development and delivery.
• Iterative Model: Focuses on refining processes through repeated cycles to improve the system at each iteration.
• Prototype Model: Involves creating an initial prototype to gather user feedback and refine requirements.

2.1.2 Waterfall Model

• A linear, sequential approach
• Each phase must be completed before proceeding to the next phase
• Stages: Requirement Analysis, System Design, Implementation, Testing, Deployment, and Maintenance

2.1.3 V-Model

• Extends the waterfall model
• Emphases Verification and Validation at different stages of the development process—during planning, design, and implementation
• Verification phases test each output in relation to inputs/requirements

2.1.4 Incremental Model

• Breaks down a project into smaller increments (segments)
• Each increment can be developed and delivered incrementally, allowing users to get value early on

2.1.5 Iterative Model

• Repeated cycles to refine and improve the system with feedback
• Focuses on refinement and improving the system at each iteration

2.1.6 Prototype Model

• Creates an initial prototype
• Used to gain user feedback and refine the requirements.

2.2 Modern Life Cycle Models

• Modern approaches to software development emphasize flexibility, adaptability, and iterative progress, catering to dynamic business needs and evolving technologies.
• They contrast to traditional models by focusing on continuous improvement, collaboration, and faster delivery.

2.2.1 Examples of Modern Life Cycle Models

• Rapid Application Development (RAD): Emphasizes speed, flexibility, and iterative development by prioritizing user involvement
• Agile Model: A flexible and iterative method that promotes collaboration, customer feedback, and rapid releases.
• Scrum: A subset of Agile focused on short development cycles (sprints) and defined roles.
• Kanban: A lean methodology that emphasizes visual workflows and limits 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, passing repeatedly through planning, design, build, and testing phases.

2.3 Overview of SDLC Stages

• Traditional methodology to maintain, develop, and replace information systems
• Consists of five phases: Planning, Analysis, Design, Implementation, and Maintenance.
• Phases are not necessarily sequential
• Each phase has specific deliverables and outcomes
• Individual companies may customize life cycles.
• Focus is on the stages of the development process, and details on these stages follow.

2.3.1 Planning

• The first phase of the SDLC in which an organization’s total needs for an information system are identified, prioritized, and arranged.

2.3.2 Analysis

• Studies current procedures and information systems, determines requirements, generates alternative designs, compares alternatives, and recommends one as the best.

2.3.3 Design

• Describes the recommended solution in logical and physical system specifications
• Defines functional features of the system independently of platform.
• Physical design translates logical specifications to tech-specific programming.

2.3.4 Implementation

• System coding, testing, installation, and ongoing support within the organization.

2.3.5 Maintenance

• The final phase of the SDLC, where the system actively maintains repairs and improvements based on user needs, reflecting evolving conditions.