System Integration & Architecture

• Methods and Approaches of System Development by Rojo, J./Odarve, C./Oñate, A/Sarsalijo, M/Bracho, J./Uy, U./Yabes, C./Battung, T. provides insight into System Integration & Architecture.

SDLC & System Development Lifecycle

• SDLC refers to the overall process of developing software from conception to deployment and maintenance.
• SDLC is a framework defining stages like planning, analysis, design, implementation, testing, deployment, and maintenance.
• SDLC framework can follow various models like Waterfall or V-model.
• The seven phases of the Systems Development Life Cycle include identifying problems, determining information requirements, analyzing system needs, designing the recommended system, developing and documenting software, testing and maintaining the system, and implementing and evaluating the system.

System Development Methods

• Ten system development methods include Waterfall, Agile System Development, Spiral Model, V-Model, Prototyping Model, RAD, Incremental Model, DevOps Methodology, LEAN Development, and Object-Oriented Development.
• The ten mentioned models/methods operate within the SDLC framework, tailoring the process to meet specific project needs, risks, and goals.
• Traditional methods: Waterfall, Spiral, V-Model Prototyping, RAD & Incremental models
• Modern methods: Agile, DevOps, OOP and Lean Development.
• RAD is considered a transitional approach between traditional and modern approaches.
• Agile methodology is a modern approach, designed to address the dynamic and unpredictable nature of contemporary software development tailored for projects requiring flexibility, rapid iteration, and close collaboration with stakeholders.
• RAD is deemed a traditional methodology stemming from its iterative nature and emphasis on user feedback, functions as a precursor to modern approaches like Agile and serves as a bridge between rigid traditional methods and adaptive, iterative methods.
• Prototyping is fundamentally a traditional methodology with iterative principles.

Waterfall

• Waterfall is a linear, sequential approach where each phase must be completed before the next begins.
• Waterfall is best suited for projects with well-defined requirements.

Agile

• Agile is an iterative and incremental approach.
• Agile focuses on flexibility, continuous feedback, and delivering working software in small increments.
• Agile is ideal for evolving requirements.

Spiral

• Spiral combines iterative development with risk management
• Spiral focuses on cycles (or "spirals") where each loop involves planning, risk analysis, development, and evaluation.
• Spiral is suitable for large, high-risk projects.

V-Model

• V-Model is a structured approach where each development phase is directly associated with a corresponding testing phase.
• V-Model includes verification (design and development) and validation (testing) activities that run in parallel.
• V-Model is a variant of the Waterfall model.

Prototyping Model

• Prototyping emphasizes building a prototype early to understand user requirements better.
• Feedback from the prototype is used to refine requirements and develop the final product.
• Prototyping emphasizes iterative design and user involvement during the SDLC phases, particularly in requirements gathering and design.

RAD (Rapid Application Development)

• RAD is a user-centered, iterative approach that emphasizes speed and rapid prototyping.
• RAD encourages the use of reusable components and collaborative development.
• RAD aligns with SDLC by compressing stages like design, development, and testing into iterative cycles for faster delivery.

Incremental Model

• Incremental divides the project into smaller, manageable parts (increments) that are developed and delivered sequentially.
• Each increment builds upon the previous one until the final product is completed.
• Incremental executes the SDLC phases.

DEVOPS Methodology

• DEVOPS focuses on collaboration between development and operations teams to automate and streamline software delivery.
• DEVOPS incorporates CI/CD (Continuous Integration and Continuous Deployment) pipelines and emphasizes monitoring and feedback.
• DEVOPS enhances the implementation, deployment, and maintenance stages of SDLC.

LEAN Development

• LEAN is inspired by lean manufacturing principles and aims to minimize waste and maximize value.
• LEAN encourages iterative development, continuous improvement, and customer-focused solutions.
• LEAN optimizes SDLC processes by focusing on efficiency and removing unnecessary steps.

OBJECT ORIENTED Development

• The object-oriented methodology uses design principles of object-oriented programming, emphasizing encapsulation, inheritance, and polymorphism.
• It models the system using objects and their interactions to represent real-world entities.
• It influences the design and implementation phases of SDLC, but the overall process follows the SDLC structure.

Additional Phases & SDLC

• Methodologies and frameworks often add unique phases or expand on the seven core SDLC phases (Planning, Analysis, Design, Implementation, Testing, Deployment, and Maintenance).
• These are introduced by various methods to address specific aspects of software development:
  • Feasibility Study - project viability and risk assessment, using Spiral, PMBOK -Risk Management - proactive identification and mitigation of risks, using Spiral
  • Prototyping and Validation - early requirement refinement and validation, using Prototyping Model, RAD.
  • CI/CD - Automation of integration and deployment, using DevOps.
  • Customer Feedback and Collaboration - incorporating continuous feedback, using Agile, Scrum, Kanban.
  • Monitoring and Optimization - ongoing performance tracking and improvement, using DevOps, ITIL.
  • User Experience (UX) Design - creating intuitive and user-friendly designs, using Design Thinking, UX-Centered.
  • Knowledge Transfer and Training - ensuring smooth adoption and operational continuity, using PMBOK, ITIL.
  • Retirement and Decommissioning - Safe phasing out of software systems, using ITIL, DevOps.
  • Compliance and Security Auditing - Adherence to standards and legal requirements, using ITIL, Agile.

Relation with SDLC

• Frameworks and methodologies explicitly designed for software development align closely with SDLC because they provide structured ways to manage its phases like planning, design, development, testing and maintenance.
• Agile, Waterfall, V-Model, Spiral, Incremental, and RAD are models within the SDLC framework, defining how to execute its stages.
• Scrum, Kanban & SAFe are specific Agile frameworks that manage.
• Other frameworks that enhance the deployment, operations and maintenance phases of SDLC, but don't directly form part of SDLC include:
  • Project Management Frameworks: PMBOK, PRINCE2 helping organize, managing the overall execution of SDLC, budgets, and resources.
  • DevOps Frameworks: CALMS, ITIL enhancing the deployment operations, and maintenance.
  • Quality Assurance and Improvement Frameworks: CMMI, Six Sigma improve the quality of the SDLC output by optimizing processes, reducing defects, ensuring that each phase delivers high-quality results.
  • Design and Analysis Frameworks: Domain-Driven Design (DDD), Unified Process (UP): Focus on the design and analysis phases ensuring a strong foundation for the rest of the SDLC.