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What Is a Kanban Cumulative Flow Diagram?

At the heart of the Kanban project management methodology is the Kanban board, which divides tasks into three columns — “To Do,” “Work in Progress,” and “Done.”

A Kanban cumulative flow diagram is an analytical tool that works alongside the Kanban board, allowing you to understand your team’s processes and identify areas for improvement. It collects all the tasks in your workflow to visualize three metrics:

  • Cycle time: The total time it takes your team to complete each task
  • Work in progress: The number of tasks your team is dealing with at a certain time
  • Throughput: The number of tasks your team can complete in a specific period

Tasks are depicted on the vertical axis of a Kanban cumulative flow diagram as bands of different colors, which correspond to a stage on your workflow. Each band shows how many tasks are at that stage of the process, with the project timeline set along the horizontal axis.


How to read a Kanban cumulative flow diagram

The ideal Kanban cumulative flow diagram shows the task bands rising in parallel over time, with the tallest band belonging to tasks in the “Done” column. This demonstrates that your workflow is stable, and your team is not overwhelmed with tasks.

You don’t want to see the “Work in Progress” band spiking in your diagram. This means that your team has more tasks arriving than they can comfortably complete, and the project could run into bottlenecks. 

Conversely, if you find that the “Work in Progress” band narrows sharply, it may be a sign that you have more capacity than you need at this stage in the project. You can then reallocate your resources accordingly.

Why Kanban cumulative flow diagrams are useful

When used correctly, a Kanban cumulative flow diagram should allow you to pinpoint potential issues before they happen. It can help you refine your processes and maintain continuous improvement, which is one of the core practices of Kanban. So if you’re hoping to boost the productivity and efficiency of your project team, a Kanban cumulative flow diagram could be just the tool you need.

Further reading
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Top Tips for Organizing Kanban Cards

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What You Need to Know About Scrumban


Kanban Principles and Practices


Kanban Tools and Software