The analytics in Kanbanize work per board. Click the Analytics icon on the top of each board to access the Analytics page.
The Analytics screen presents 5 categories: Cycle Time, Throughput, WIP, Flow, Forecasting, each available as a tab item on the page. Click on a tab button to view the charts for each of the respective metrics. The Cumulative Flow Diagram belongs to the Flow category.
Note: Before start using the analytics make sure that you have configured the Cycle time tracking for the respective board. You can choose which columns from your workflow to be included in the analytics as well as for the calculation of the card "cycle time". To learn how to configure cycle time per board, please check the dedicated article.
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.
How to set up the Cumulative flow diagram?
From the left side of the panel, you can control which data you can see on the chart within a predetermined time frame.
First, you define the timeframe ("Requested After" date and "Finished Before" date).
Important: The chart will visualize only cards that have entered your flow after the "requested date" that you define. In case that the cards were in your flow before the requested date and are completed within the "finished before" date, they won't be displayed.
Then you select the workflows that you want to analyze using the Cumulative Flow.
The chart takes into consideration all cards from the selected workflows. Note that you can add single or multiple workflows.
In addition, you can apply card filters (Add cards filter). For example, you may want to see only cards with high priority or cards that are of a certain type.
Important:
The analytics use one calendar day as the lowest possible time unit.
For example: The card was created 30 minutes ago and was moved to "In progress". The system shows 1 day for this card. The card was created late yesterday at 23:00 P.M. and you take a look at the chart in the morning at 9:00 A.M. (i.e. around 10 hours after the creation). The system will show 2 days as the card has been created yesterday and is still being worked on Today.
The Calendar time unit is used for analytics due to the fact that most of the modern Kanban systems are driven by client requests. As such, clients expect exact delivery dates or ranges that are calendar-based. They do not care about holidays, working hours, man-days, cycle, and lead times.
In case that you need precise cycle and log times for internal reporting, use the Advanced search capabilities with the different charts views and widgets.
What's this diagram telling us?
The cumulative flow diagram shows the accumulation of work overtime. 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 more than 500 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 the bottom line 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.
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 start to expand, it means that the stage holds more work items that 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 to establish Work in Progress (WIP) limits.
The WIP limit improves your throughput and reduces the number of unfinished tasks. The 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. 
- Summary Statistics:
All values in this table are calculated averages. Each stage in workflow is represented as a row in the Table. Note: 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.