Main takeaway:

Choose Scrum when you need fixed-length iterations, clearly-defined roles, and a strong cadence for inspection, planning, and delivery. Opt for Kanban when you prefer continuous flow, flexible scope, and visual control over work-in-progress. Hybrid Scrumban can provide a path when you need elements of both.

1. Agile Roots, Different Roads

Both frameworks apply the Agile values of transparency, inspection, and adaptation.

Scrum embodies them through short, time-boxed sprints and five formal events.
Kanban delivers them through a visual pull-system, explicit work-in-progress (WIP) limits, and continuous flow.

2. What Exactly Is Scrum?

Empirical framework founded on the pillars of transparency, inspection, adaptation.
Core roles: Product Owner, Scrum Master, Developers.
Artifacts & commitments: Product Backlog → Product Goal, Sprint Backlog → Sprint Goal, Increment → Definition of Done.
Events: Sprint Planning, Daily Scrum, Sprint Review, Sprint Retrospective, plus the Sprint itself.
Cadence: Fixed-length sprints (1-4 weeks) that end with a potentially shippable increment.

3. What Exactly Is Kanban?

Lean-inspired visual workflow that starts with existing processes and evolves incrementally.
Four foundational principles: start with what you do now, pursue incremental change, respect current roles, encourage leadership at all levels.
Key practices: visualize work, limit WIP, manage flow, make policies explicit, implement feedback loops, seek improvement.
Cadence: Continuous; items are pulled when capacity is free rather than scheduled into sprints.

4. Side-by-Side Comparison

Dimension	Kanban	Scrum
Delivery rhythm	Continuous flow	Time-boxed sprints (1–4 weeks)
Roles required	None mandatory; teams self-define	Product Owner, Scrum Master, Developers
Planning style	Just-in-time based on WIP & past throughput	Sprint Planning forecasts work for the sprint
Change policy	Changes allowed anytime; cards keep moving	Scope frozen during sprint unless sprint is aborted
Key metrics	Cycle/lead time, throughput	Velocity, burndown, sprint goal success
Board reset	Never; board is continuous	Reset after every sprint
Best for	Service / support queues, unpredictable demand, small teams	Product development with evolving but plannable features, cross-functional teams

5. Similarities Worth Noting

Pull-based mindset: Work is only started when capacity exists.
Visual management: Boards expose status, blockers, and priorities.
Continuous improvement: Retrospectives in Scrum, explicit policies & metrics in Kanban.
Agile compatibility: Both embrace iterative, customer-focused delivery.

6. When to Choose Scrum

Scrum excels when you need:

Clear cadence and predictability for external stakeholders.
Cross-functional collaboration on complex features that require tight integration.
A framework for learning Agile—its prescriptive structure guides new teams.

Typical scenarios: new product builds, feature-driven roadmaps, regulatory increments requiring Definition of Done compliance.

7. When to Choose Kanban

Kanban shines when you need:

Rapid reaction to incoming work (e.g., support, DevOps, marketing requests).
Small or specialist teams where prescribing roles wastes capacity.
Flow optimization: slimming cycle time and surfacing bottlenecks via WIP limits.

Typical scenarios: production support queues, content pipelines, infrastructure maintenance.

8. Not Either/Or: Enter Scrumban

Hybrid Scrumban blends Scrum's sprint goal discipline with Kanban's flow and WIP controls. It fits:

Teams migrating from Scrum to Kanban (or vice versa).
Projects needing both release cadence and continuous intake of urgent items.
Organizations experimenting toward their ideal workflow without a big-bang change.

9. Implementation Tips

Start small, visualize everything—sticky notes or digital boards make impediments obvious.
Limit WIP early to reduce multitasking and expose process debt.
Respect roles (Scrum) or policies (Kanban); both guard against hidden work and scope creep.
Measure what matters: pick 1–2 lag metrics (cycle time or velocity) and 1–2 lead metrics (WIP, commitment reliability) to drive improvement.
Review and adapt every sprint (Scrum) or at least monthly (Kanban) to tweak limits, workflows, or definitions of done.

Summary

Scrum gives structure: time-boxed sprints, clearly-defined roles, and sprint goals suit product feature work.
Kanban gives flexibility: continuous delivery, WIP limits, and workflow visualization suit support, operations, or highly variable queues.
Scrumban offers a pragmatic bridge when your context mixes the two.

Selecting the right framework means matching its strengths to the nature of your work, team maturity, and stakeholder expectations. Start where you are, inspect results, and adapt—exactly as Agile intended.