Agile Principles & Methodologies

Core values, principles, and major frameworks for iterative, adaptive software development.

Agile Manifesto (2001)

Values

Individuals and interactions over processes and tools
Working software over comprehensive documentation
Customer collaboration over contract negotiation
Responding to change over following a plan

Principles (Selected)

1. Early and continuous delivery of valuable software
2. Welcome changing requirements, even late in development
3. Deliver working software frequently (weeks, not months)
4. Business people and developers work together daily
5. Build projects around motivated individuals — trust them
6. Face-to-face conversation is most effective
7. Working software is the primary measure of progress
8. Sustainable pace — sponsors, developers, users maintain constant pace indefinitely
9. Continuous attention to technical excellence and good design
10. Simplicity — maximize the amount of work not done
11. Self-organizing teams produce best architectures/requirements/designs
12. Regular reflection on how to become more effective

Common Practices Across Frameworks

Insight: These aren't competing — they're complementary. Effective teams blend them.

Scrum

Roles

Events (Time-boxed)

Artifacts

Key Concepts

• Definition of Done — Shared understanding of "complete"; applies to every Increment
• Sprint Goal — Single objective for the Sprint; provides focus
• Product Goal — Long-term objective for the Product

When Scrum Works Well

• Complex adaptive problems
• Cross-functional teams (2-10 people)
• Work can be planned in Sprint increments
• Product Owner available and empowered

Kanban

Three Principles

1. Visualize — Make work and workflow explicit
2. Limit WIP — Stop starting, start finishing
3. Enhance flow — Optimize for smooth, predictable delivery

Core Practices

Kanban Metrics (Mandatory Flow Measures)

Little's Law: WIP = Throughput × Cycle Time — More WIP = longer cycle time

When Kanban Works Well

• Maintenance/support work (unplannable)
• Continuous flow preferred over iterations
• Teams respecting current roles (evolutionary change)
• Need for explicit workflow visualization

Extreme Programming (XP)

Values

Communication, Simplicity, Feedback, Courage, Quality Work

Core Practices (Interconnected — do together)

XP Lifecycle

Quarterly Cycle (Release)
    │
    ├── Weekly Cycle (Iteration) × N
    │       │
    │       ├── Monday: Plan week (customer picks stories)
    │       ├── Tue-Thu: Develop (pair, test-first, refactor, CI)
    │       ├── Friday: Demo + Retrospective
    │       │
    │       └── Slack: Low-priority tasks to drop if behind
    │
    └── Spike: Time-boxed research for unknowns

When XP Works Well

• Co-located teams (2-10 people)
• High change rate, unclear requirements
• Team embraces discipline (pairing, TDD, CI)
• Customer available full-time

Choosing / Blending

Decision Factors

Hybrid Approaches (Common)

• Scrumban — Scrum events + Kanban board/WIP limits + flow metrics
• Scrum + XP — Scrum framework with XP engineering practices
• Kanban + XP — Flow-based with XP technical practices

Disciplined Agile Insight

"Scrum and Kanban are not merely different sets of practices, they are based on different models of transformation. Scrum urges big changes; Kanban involves small evolutionary changes. DA takes a guided continuous improvement approach."

Scaling Frameworks (Brief)

Anti-Patterns

Related Notes

• Scrum Guide — Detailed Scrum reference
• Kanban Method — Kanban deep dive
• Extreme Programming — XP practices detail
• Team Topologies — Team structure for flow
• Engineering Culture — Blameless, learning organization
• Test Driven Development — TDD as XP practice
• CI CD Best Practices — CI as XP practice

Sources: Agile Manifesto, Scrum Guide (scrumguides.org), Kanban Guide (kanbanguides.org), Extreme Programming Explained (Kent Beck), Agile Alliance, PMI Disciplined Agile, Software Engineering: A Modern Approach, Martin Fowler