Ah yes, the cumulative flow diagram.
The agile metric that looks intimidating at first, but quickly shows its usefulness, since you get 3 metrics for the price of one.
With the cumulative flow diagram in your hand, you will quickly get a trend of, and insight into, what has been completed, what is in progress and what is yet to be started. This 3-for-1 deal comes handy when you want to identify bottlenecks fast, and when you want to create a baseline for your team's work distribution.
Let’s explore the 3-in-1 metric, also known as the cumulative flow diagram below.
What is a cumulative flow diagram?
If learning about one metric is tough, then you might think that learning three in one is thrice as tough. Not really. I will provide (as always), an example that is relatable for you, so you have the right foundation before we get to the definition of the cumulative flow diagram. The scenario we'll use is the classic activity of relocating into a new home.
So, let's say that you are moving into a new home in one week, and you have to pack everything into boxes by then. Ambitious, but you are ready for the challenge.
Your current home has 5 rooms, including kitchen and hallway. You immediately start with your bedroom, and before finishing that, you switch tactics and pack all items in the hallway into boxes. After the first day, you update your progress. Some rooms will be "unpacked", the bedroom would be "still packing" and the hallway would be marked as "packed".
If we visualize your progress after the first day on a chart, it would represent different stages of you getting ready to move into a new home:
- One section of the chart would show the unpacked rooms
- Another section of the chart would show rooms that are still being packed
- The third section would show the rooms that you have already packed
As you continue packing throughout the week, the chart would evolve. You will have less rooms being "unpacked", the "still packing" section would fluctuate depending on how many rooms you are packing at once, and the "packed" section would grow steadily as more rooms are completed. By stacking these sections on top of each other to show your progress throughout the week, you will have created a cumulative flow diagram.
The key takeaway is that a cumulative flow diagram does not just measure how much is left or how much is done. It gives a complete picture of all stages of work, just like our moving example, where some rooms remain unpacked, some are in progress, and some are fully packed. The cumulative flow diagram then helps you balance your workflow, and spot inefficiencies when work is piling up, so you can ensure that progress is flowing smoothly. As an example, if you were working on all the rooms at once, you would probably complete a full room a bit slower, than if you focused on only one room at a time. A cumulative flow diagram would help you identify this bottleneck immediately.
Now, let's create a simple definition that you can remember.
Simple definition of a cumulative flow diagram
A cumulative flow diagram is a graph that tracks three metrics simultaneously over time; what has been completed, what is in progress and what is yet to be started.
