How do I use a Cumulative Flow Diagram to identify bottlenecks in my process?

All answers to this question.

Think of the CFD as a river. You want the bands to be smooth and parallel. If a band (like "Testing") starts widening, that’s a bottleneck; work is entering that stage faster than it’s leaving. If a band is narrowing, you have "starvation," meaning that stage has too much capacity and is waiting for work from the previous step. A sudden vertical jump in all bands usually means a large batch of work was moved at once, which is a sign you aren't working in small batches. Analyzing these slopes helps you predict your future delivery dates based on the average "burn-up" rate of the total scope.

   Answered 2025-02-12 by Patricia Williams

That river analogy is helpful, but what do you do when the "Done" line is flat for a long period? Does that always indicate a massive bottleneck, or could it be a sign that the team is working on a single, massive 'Epic' that hasn't been broken down into smaller, deliverable User Stories?

   Answered 2025-02-14 by David Anderson

• David, a flat 'Done' line is a major red flag for 'Batching'. It usually means the team is waiting for a "Big Bang" release. I always push our guys to break those Epics down so we see a steady, stair-step climb in the 'Done' section. It provides much better visibility and reduces the risk of late-stage failures.

     Commented 2025-02-16 by Linda Martinez

CFDs are also great for showing "Scope Creep." If the top line (Total Work) is rising faster than the bottom line (Done), you'll never finish. It’s a great visual for the Product Owner.

   Answered 2025-02-18 by Michael Brennan

• Spot on, Michael. I used our CFD to show our PO that we added 50% more work than we finished last quarter. It was the only way to get them to stop adding new 'urgent' tasks.

     Commented 2025-02-20 by Patricia Williams