Scrum vs Kanban
Sprint-based iterations vs continuous flow
Scrum and Kanban are both agile project management methodologies, but they structure work differently. Scrum organizes work into fixed-length sprints with defined roles and ceremonies, while Kanban focuses on continuous flow with work-in-progress limits and visual boards. Both aim to deliver value iteratively, but their mechanics suit different team dynamics.
Scrum
Scrum is an agile framework introduced by Ken Schwaber and Jeff Sutherland in the 1990s. Work is organized into fixed-length iterations called sprints (typically 1-4 weeks). Each sprint begins with planning, includes daily standups, and ends with a review and retrospective. Scrum defines specific roles (Product Owner, Scrum Master, Development Team) and artifacts (product backlog, sprint backlog, increment). Its structure provides predictability and regular delivery cadence.
Kanban
Kanban is a workflow management method inspired by Toyota's manufacturing system, adapted for knowledge work by David J. Anderson in the 2000s. Work items flow through stages on a visual board (e.g., To Do, In Progress, Done), with strict work-in-progress (WIP) limits at each stage. Kanban has no prescribed roles, no fixed iterations, and no required ceremonies. Its focus is on visualizing work, limiting WIP, and optimizing flow.
Key Differences
- **Iterations**: Scrum uses fixed-length sprints. Kanban uses continuous flow with no mandated iterations. - **Roles**: Scrum defines specific roles (Product Owner, Scrum Master). Kanban does not prescribe roles. - **Planning**: Scrum plans work for each sprint upfront. Kanban pulls items continuously as capacity becomes available. - **Changes**: Scrum discourages scope changes during a sprint. Kanban allows new items to be added at any time (subject to WIP limits). - **Metrics**: Scrum tracks velocity (story points per sprint). Kanban tracks cycle time (how long items take from start to done) and throughput. - **Ceremonies**: Scrum has prescribed events (sprint planning, daily standup, sprint review, retrospective). Kanban has no required meetings, though teams often add them.
When to Use Each
**Use Scrum** when your team needs structure and predictable delivery cadence, when working on complex projects with many unknowns, when stakeholders need regular demos and progress reports, or when the team is new to agile and benefits from a defined framework. **Use Kanban** for support and maintenance teams with unpredictable, incoming work, when you need maximum flexibility to reprioritize, for teams already performing well that want to optimize flow, or when fixed-length iterations create artificial pressure or waste.
Analogy
**Scrum** is like a relay race: the team commits to a fixed distance (sprint), runs it together, then regroups before the next leg. Pacing and handoffs are planned. **Kanban** is like a highway with metered on-ramps: cars (work items) flow continuously, speed is regulated by controlling how many cars enter at once (WIP limits), and the goal is smooth traffic, not finishing in laps.