In this article:
1. Introduction to the Cumulative Flow Diagram
2. What Is This Diagram Telling Us?
2.1. Approximate Average Cycle Time
2.2. Work In Progress
2.3. Average Throughput
2.4. Summary Statistics
You can find more information about the Analytics module in the dedicated article.
Important: In Version 11.0, we introduced a new version of the Analytics module that affects some charts, including the Cumulative Flow Diagram. The points below describe the old CFD functionalities. To see how the new version differs, please check pt. 3.
1. Introduction to the Cumulative Flow Diagram
The Cumulative Flow Diagram aims to show the stability of your process over time. It tracks and accumulates each task that has ever entered or progressed to any stage of your workflow.
Using the diagram, you can get an idea of how your work in progress, throughput, and cycle time change over time.
- The "X" axis represents a timeline.
- The "Y" axis is the actual number of the work items. This could be tasks, projects, or anything that you measure on the selected workflow.
Important:
The Cumulative Flow Diagram allows for cycle time recalculation based on working days.
Note that the X-axis would still display all calendar days/weeks but the average cycle time for the period will be recalculated - this can be seen by hovering the mouse over the graph data.
For example, if a card was started on Friday and finished on Monday, the setting would read 4 days by default (as it would take Saturday and Sunday into consideration).
With the working days option enabled, the tooltip (when hovering with the mouse) would read a cycle time of 1 day for that card, as time spent in the stages would be recalculated to exclude the weekend.
If you need precise cycle and log times for internal reporting purposes, use the Advanced search capabilities with its different chart views and widgets.
Dataset Configuration
Use the left-side menu to filter your data. You need to select at least one of the fields: End Date, Start Date, or Created at, as well as at least one workflow.
You can also enable these options:
- Ignore the cycle time configuration for the selected workflow(s) — checkmark this if you want the system to disregard the cycle time settings for the selected workflow(s).
- Ignore the block time in the queue columns — checkmark this if you don't want the system to account for the time cards were blocked when in queue columns.
2. What Is This Diagram Telling Us?
The Cumulative Flow Diagram shows the accumulation of work over time. Every stage of the workflow is represented by a differently colored band. Whenever you complete a task, the number of cards in your "Done" stage rises permanently.
In the example below, you may see that the respective workflow has accumulated nearly 200 work items since the selected date.
Note: If you ever see a band going down, then the chart is incorrect since tasks should never disappear.
In general, you can spot whether your process is stable with a single glance by looking at how the top and bottom lines of each band in your Cumulative Flow Diagram are progressing.
Approximate Average Cycle Time
The horizontal distance between your first and last stage shows the approximate average cycle time for your tasks meaning the time it took you to progress a task from being Requested to Done. When all the bands are progressing in parallel, this means that your process is smooth and the cycle time is consistent.
TIP: Go to Layout in the Controls for this chart and checkmark "Show data control." This option allows you to zoom in and out of a specific interval within the selected time frame, so you can get a better overview of the band's width.
You can fine-tune your selection by also scrolling vertically.
Work In Progress
The diagram visualizes the number of work items that are in progress at each stage of your flow.
This can be measured using the vertical distance between the lines of each band.
If any of the bands starts to expand, it means that the stage holds more work items than it can handle, i.e. tasks are arriving faster than can be processed. This immediately increases cycle time and you need to take some action. In this case, we recommend you establish Work in Progress (WIP) limits.
The WIP limit improves your throughput and reduces the number of unfinished tasks. Team members pull work as they finish what they started.
Average Throughput
Having bands that are progressing in parallel also means that your average throughput is stable and new tasks are entering your workflow in parallel to those that are leaving it. This is the ideal outcome and shows that you can focus your efforts on shortening the cycle times of your assignments.
The bottom blue line of your diagram visualizes the number of deliverables within a certain date.
The slope of that line between any two points shows the average throughput.
The metric is average because not all of the tasks that have entered the stage necessarily leave it at the predetermined time frame. They might be moved to the next stage later in time.
Summary Statistics
You can access the Summary statistics at the top of the Controls for this chart.
All values in this table are calculated averages. Each stage in the workflow is represented as a row in the Table. The table provides reliable results only when the Kanban system is stable and there is a continuous flow. If there are too many days when 0 items enter the flow or if there is no movement of items in the established process, bias might occur.
Arrival Rate (items/day) - the average number of items per day that enter the flow.
Throughput (items/day) - the average number of items per day that are passing through the system.
Cycle Time (days) - the average number of days that items spend in the stage.
Daily WIP (items) - The average number of "work in progress" items in the stable system.
The top row named "System" provides overall results for your process, where:
- Arrival Rate (items/day) gets the maximum value for the columns.
- Throughput (items/day) gets the minimum value for the columns. (this is the average number of items per day that are passing through the system)
- Cycle Time (days) - sums up the cycle time for all columns.
-
Daily WIP (items) - The average number of "work in progress" items in the stable system.
Additional chart control notes:
- Rate Lines — show the arrival and departure rates at which cards enter or exit the flow for the selected time period.
- WIP Tooltips — shows all in-progress items in the flow for the selected day, either as a total number for the flow (System) or per workflow (Stages).
- Cycle Time Tooltips — shows the cycle time of all cards for all selected workflows (System) or per workflow (Stages).
3. Cumulative Flow Diagram: New Version
The new version aims to show more precise time metrics, which is why we no longer have an “artificial” Done column. In the CFD, the last column you select from the workflow stages is considered the Done column, but that does not change the Done date of the cards.
Additionally, if a card hasn't passed through the first selected column, the system will assign an entry date for any skipped columns to ensure the diagram is displayed correctly and the arrival rate is accurately calculated. This will not affect the card’s cycle time!
Here is how the new version also differs from the old CFD:
Dataset Configuration
- The “Ignore Cycle Time Configuration” checkbox has been replaced with the new “Show full workflow structure” option available in the controls menu.
- The “Ignore Block Time in Queue Columns” checkbox has been removed.
Chart Controls
Arrival Date for Returned Cards
This option appears in the Chart Controls only when the system detects cards that have been moved backward in the workflow. You have three options for how you want to track those cards:
- First Entry Date — Only the first time a card enters the respective column is considered.
- Last Entry Date — Only the most recent time a card enters the column is taken into account.
- Count Every Entry — Every instance of a card entering the column is counted, resulting in a higher accumulation of WIP and cycle time data.
Important: Depending on the tracking option you select, if many cards have been moved back and forth in the workflow, you may encounter negative WIP numbers or situations where the lower bands cover the upper bands in the diagram.
Summary Statistics
The selected option in the “Arrival date for returned cards” setting will be reflected in the summary statistics for a more accurate presentation. Cards are counted as arrived or completed only for the columns they have passed through.
Note: The cycle time data in the Summary Statistics table depends on the columns selected in the Workflow Columns menu.
Workflow Columns
By default, the system will select only the columns in your workflow that are included in the cycle time configuration. If you want to include queue columns, select the “Show full workflow structure” checkbox and manually select the columns you want to include in the diagram.