Analyze your work in progress. Track how much work your team delivers. Evaluate your process health.
With the Cumulative Flow Diagram for ZenHub (CFD), each colored band represents a pipeline in your ZenHub board. The horizontal axis shows a timeline and the vertical axis displays the number of issues in your pipelines. The size of the colored areas indicates how many issues are currently on each pipeline.
Adhere to your WIP limits and strive to keep the number of tasks in each pipeline within the maximum value - this is the key to achieving a consistent, predictable workflow.
You can use CFD to gain a concise image of how your team performed on each date. By hovering over the graph, you can see the number of issues in progress on the selected date, along with the number of issues that were completed so far.
By switching between 'process' and 'states' in your WIP tooltip, you can see both your total WIP across your process and the WIP of each column from your ZenHub board.
The horizontal difference between the top and the bottom line of a CFD area is your approximate average cycle time. Approximate average cycle time shows how long it took for issues to be completed on a certain date, on average.
Comparing the approximate average cycle time from your CFD with the exact average cycle time from your Cycle Time Histogram for ZenHub can give you a good understanding of your process performance. If the values are roughly equal, this means that you’re maintaining a stable system.
The bottom line of your CFD represents the ‘Done’ state from your process. By observing that line on the CFD, you can measure the amount of work your team has delivered. Determine your average throughput by measuring the slope between any two points on the line. A productive and self-organized team will be able to complete tasks quickly which will translate into a rapidly growing ‘Done’ area.
A flattening gradient in your ‘Done’ area should be treated as a warning sign, as it shows you that your team is struggling to deliver results.
The top line of the graph represents the arrival rate of tasks, while the bottom line shows their departures. These numbers cover the rate at which you start new work and finish outstanding work.
In order to achieve a predictable flow of work, you need to monitor how the lines move over time. In stable systems arrival rate and departure rate lines grow in sync.
Use the ‘Arrival and Throughput Rates’ widget to track how your arrival and throughput rates change over the course of a selected time frame. Ideally, these lines should overlap with each other.
If the arrival line goes up, this means that you’re starting work faster than you finish it. This is an indicator that your team is working on more tasks than they are able to handle at a time, which would reduce your team’s efficiency and increase your cycle times.
Along with undertaking an evaluation of your system’s stability, The Cumulative Flow Diagram for ZenHub enables you to promptly identify problem areas as soon as they arise. In a stable system, the average arrival rate is roughly equal to the average throughput rate which means that tasks are arriving into the process at the same speed at which others are leaving it.
Based on Little's Law, Average Cycle Time = Average Work In Progress / Average Throughput. The more you adhere to the terms of this equation, the healthier your process will be.
The Cumulative Flow Diagram for ZenHub gives you an instant insight into the exact amount of work that exists in each state of your process. If one or more of the areas that represent WIP start expanding, this indicates a problem bottleneck stemming from your workflow.
Don’t forget to consider any changes that occur as an explanation for an unexpected spike in your activity. A public holiday or new team member joining the team would inevitably affect the shape of your CFD bands.