To find a possible delay in a cumulative flow diagram, look for a status band that grows wider while completed work increases more slowly. Then inspect the tasks in that status. The chart shows work accumulating over time, but you still need owners, blocked reasons and dependencies to explain why it is waiting.
Understand the axes and bands first#
Time runs along the horizontal axis. The vertical axis counts work items. Each colored band represents the number of items in a workflow state at each point in time. Read the band thickness as the count in that state, rather than reading the upper boundary as the state count.
Check how your tool handles cancelled, reopened and archived items. A report based on current task records can change after scope or status definitions change. Keep the scope stable before comparing periods.
Three patterns worth investigating#
- Active work widens: work is starting faster than it is leaving that state. Check concurrent projects, task size and hidden waiting.
- Blocked work widens: more items are explicitly stuck. Group them by dependency or blocked reason.
- Completed work flattens: fewer items are finishing in the selected scope. Check missing updates, holidays and whether the work mix changed.
A widening band identifies a question, not an employee at fault. Teams sometimes leave waiting work marked active, so status discipline matters as much as chart design.
Worked example: review work grows for two weeks#
In a hypothetical release team, the active band keeps widening while completed work grows slowly. Inspecting the oldest active tasks reveals that several are actually waiting for one reviewer. Update those records and confirm when they became ready for review.
The manager agrees a common review order and limits new starts. At the next review, look for older review items finishing and the ready queue shrinking. A thinner band caused only by moving tasks to a different label does not demonstrate a delivery improvement.
Use cycle time and aging work beside the chart#
A cumulative flow diagram provides an aggregate pattern. Cycle time describes elapsed time after work starts. Aging work highlights unfinished items that might disappear from a completed-items average. Review all three with the same task scope and date conventions.
A mean cycle time can improve because the team completed many small tasks while a critical large task remains blocked. Open the oldest unfinished dependencies before changing a delivery forecast.
Check the chart in Commandix#
Open Flow Analytics and select a reporting period. Compare the status chart with current workload and aging work. If the historical chart is empty, verify that status transitions exist in that period. Current open work can be present even when the history needed for the chart is missing.
Record the suspected queue, the underlying tasks and the proposed change in the review notes. Use the next comparison to test that explanation.
Related guide: Measure lead time and cycle time without a manual status report.
Frequently asked questions#
Does a widening band prove a bottleneck?#
It shows that items are accumulating in a state. Check the underlying tasks and downstream impact before deciding whether that state limits the project result.
Can I read exact cycle times from the chart?#
Aggregate chart distances can be misleading when items vary or overtake each other. Use recorded task timestamps for item-level cycle time.