Kanban: Visual Flow and Efficiency

Kanban is an agile method focused on visual workflow management.

Originating in the Toyota production system (Lean Manufacturing), its name literally means "poster" or "signboard" in Japanese.

It uses a board (Kanban Board) to represent the stages of the process and cards for work items, moving them across the board as they progress.

Unlike Scrum, which is based on fixed-time iterations (Sprints), Kanban focuses on continuous flow and optimizing how work moves through the system.

Its main goal is to improve efficiency, reduce cycle times and make bottlenecks visible so that they can be addressed.

Kanban Principles (Visualize, Limit WIP, Manage Flow, Kaizen)

Kanban is underpinned by four fundamental principles and six core practices (although they are often summarized in the principles):

• Visualize Work Flow: Make the process and the work flowing through it visible via the Kanban board. This allows everyone to understand the current state of the system.
• Limit Work In Progress (WIP): Set explicit limits on how many items can be in each stage of the process simultaneously. This avoids overload, reduces context switching and helps work flow more smoothly, shortening turnaround times (based on Little's Law).
• Manage the Flow: Monitor, measure and optimize workflow. The goal is to maximize value delivery by moving work predictably and efficiently, identifying and eliminating bottlenecks.
• Make Process Policies Explicit: Clearly define workflow rules (e.g., criteria for moving a card, WIP limits) so that everyone understands and applies them consistently.
• Implement Feedback Loops: Establish regular points to review the flow and process (similar to retrospectives).
• Improve Collaboratively, Evolve Experimentally (Kaizen): Encourage continuous process improvement through team collaboration and experimentation based on data and scientific models.

The Kanban Board and WIP Limits

The Kanban Board is the central tool for visualizing the flow. It consists of columns that represent the different states or stages that a work item goes through (e.g., To Do, In Process, In Review, Done).

Cards (representing tasks, user stories, etc.) move from left to right across these columns as they progress.

WIP Limits are explicit restrictions on the maximum number of cards allowed in a column (or set of columns) at a time, except usually in "To Do" and "Done".

These limits are crucial: they force the team to complete work before starting new work, prevent bottlenecks, encourage collaboration (if a column is full, team members can help in earlier or later stages), and improve the overall flow. WIP limits are decided and adjusted by the team.

Advantages and Applications of Kanban

Kanban offers several advantages:

• Easy implementation and fit: It can be applied on existing processes without initial disruptive changes.
• Flexibility: It does not impose fixed time iterations, adapting well to jobs with changing priorities or irregular input flows.
• Transparency: Visualizes work and bottlenecks for the entire team.
• Focus on flow: Optimizes delivery speed (cycle time).
• Waste reduction: By limiting WIP and managing flow.

It is especially useful in applications such as: operations teams, technical support, maintenance, manufacturing, and software development where continuous flow is more natural than defined sprints, or where there are many interruptions.

Summary

Kanban is an agile method focused on visual workflow management. It uses a board to represent stages and cards for the work.

Unlike Scrum, it focuses on continuous flow, not Sprints. Its principles include: Visualize Flow, Limit WIP, and Manage Flow.

Work in Progress (WIP) limits are crucial. They prevent overload and improve flow. It is useful for support or operations.