Chapter 2: System Development Life Cycle Models

Chapter 2: System Development Life Cycle Models

• This chapter introduces models for system development
• The learning objectives are to identify traditional models, explain differences between models, and list SDLC stages.

2.1 Traditional Life Cycle Models

• Traditional Life Cycle Models refer to structured methods in software and system engineering.
• These models are linear, sequential, and have clearly defined stages.

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): This model extends the Waterfall Model by incorporating verification and validation activities at each stage of the development process.

2.1.2 More Traditional Life Cycle Models

• Incremental Model: Divides a project into smaller, manageable segments for incremental development and delivery.
• Iterative Model: Revisits and refines processes through repeated cycles to improve the system at each iteration.
• Prototype Model: Develops an initial prototype to gather user feedback and refine requirements.

2.1.3 Visualization of the Waterfall Model

• The diagram displays the progressive stages of the model, including:
  • Requirement Analysis
  • System Design
  • Implementation
  • Testing
  • Deployment
  • Maintenance

2.1.4 Visualization of the V-Model

• A "V" shaped illustration demonstrates the verification and validation phases working opposite to the development phases.

2.1.5 Visualization of the Incremental Model

• The illustration visually presents the phases of an incremental development process.

2.1.6 Visualization of the Iterative Model

• The illustration displays the iterative cycle used in this development approach. It emphasizes the process of refining system aspects through repeated cycles.

2.1.7 Visualization of the Prototype Model

• The illustration shows a linear progression of steps involved in building, refining, and testing a prototype with the feedback of the customer included.

2.2 Modern Life Cycle Models

• Modern Life Cycle Models are contemporary approaches focusing on flexibility, adaptability, iterative progress, catering to dynamic business demands and evolving technologies.
• These models emphasize continuous improvement, collaboration, and faster delivery.

2.2.1 Examples of Modern Life Cycle Models

• Rapid Application Development (RAD): This methodology focuses on speed, flexibility, and iterative development to deliver a working product quickly, minimizing planning and maximizing user involvement.
• Agile Model: This approach prioritizes flexibility, collaboration, customer feedback, and the delivery of small, incremental releases.
• Scrum: A subset of Agile, focusing on short development cycles (sprints) and defined roles (Scrum Master and Product Owner).
• Kanban: A lean methodology that visualizes workflows and limits work-in-progress to improve efficiency.
• DevOps: Combines development and operations teams to enhance collaboration, automate processes, and enable continuous delivery and integration.
• Spiral Model: This model combines iterative development with a risk-driven approach, repeatedly passing through planning, design, build, and testing phases.

2.3 Overview of SDLC Stages

• Traditional methodology for developing, maintaining, and replacing information systems.
• The methodology consists of five phases:
  • Planning and Selection
  • Analysis
  • Design
  • Implementation
  • Maintenance
• Phases are not always sequential.
• Each phase includes a specific deliverable or outcome.
• Companies often customize their life cycle based on their needs.

2.3.1 SDLC Stages - Planning

• This is the initial stage where information system needs are identified, analyzed, prioritized and arranged.

2.3.2 SDLC Stages - Analysis

• Involves studying current procedures and information systems
• Determining requirements
• Generating alternative designs
• Comparing alternatives
• Recommending the best alternative

2.3.3 SDLC Stages - Design

• Describes the recommended solution (logical and physical specifications)
• Defines the functionalities in a system design independent of the platform.
• Converts logical specifications into technology-specific details for programming and system construction.

2.3.4 SDLC Stages - Implementation

• The information system is coded, tested, installed, and maintained within the organization.

2.3.5 SDLC Stages - Maintenance

• The system is repaired and improved to reflect evolving business conditions.