Kanban vs Scrum

Kanban and Scrum both follow Agile values, but they organize work differently. Understanding their differences helps a team pick the right approach for its situation.

Structure Comparison

Scrum:   Fixed sprints, fixed roles, fixed events
Kanban:  Continuous flow, flexible roles, optional events

Time Boxes

Scrum locks work into sprints that last a set number of weeks. Kanban has no fixed time box. Tasks move through the board whenever they are ready, regardless of any calendar deadline.

Roles

Scrum requires three defined roles: product owner, Scrum Master, and development team. Kanban does not require any specific roles. A team can apply Kanban on top of its existing structure without changing job titles.

Change During the Cycle

A Scrum team commits to a fixed set of backlog items at the start of a sprint and avoids adding new items midway. A Kanban team can add a new task to the backlog at any time, since no sprint commitment exists.

Measuring Progress

Scrum tracks velocity, or story points completed per sprint. Kanban tracks cycle time and throughput, as covered in the previous topic. These numbers serve a similar purpose but suit different working styles.

A Simple Diagram of Both Approaches

Scrum:   [Sprint 1: Plan-Build-Review] -> [Sprint 2: Plan-Build-Review]
Kanban:  Task A -> Task B -> Task C -> Task D (continuous, no fixed cycle)

Layman's Example

Scrum resembles a train that departs at fixed times with a planned set of passengers for each trip. Kanban resembles a taxi service where a car picks up the next passenger whenever it becomes free, with no fixed schedule.

When to Choose Each Framework

Scrum suits teams building new features in planned batches, such as a product team launching releases every few weeks. Kanban suits teams handling unpredictable incoming work, such as a support team responding to customer tickets as they arrive.

Combining Both Approaches

Some teams blend ideas from both frameworks, an approach often called Scrumban. They might keep Scrum's sprint planning while adopting Kanban's WIP limits to manage flow more carefully within each sprint.

Key Takeaway

Scrum organizes work into fixed cycles with defined roles, while Kanban manages a continuous flow of tasks with flexible structure. Teams choose based on how predictable and steady their incoming work tends to be.