A CFD tracks the number of tasks in each stage over time, providing a visual overview of how work is progressing through the workflow. A stable cumulative flow diagram indicates a smooth process, while bottlenecks appear as a widening gap in a specific stage. This helps in identifying stages where tasks pile up, highlighting areas for process improvement or resource reallocation.
Figures 4-18 and 4-19 illustrate a typical CFD in a standard digital Kanban tool:
Figure 4.18: Cumulative Flow Diagram (Source: Jira)
Figure 4-18 above shows Jira CFD visualizing a "Flow Load" over time, displaying the progression of story points across different task stages: To Do, In Development, In Testing, Pre-Release, and Done. The rising trend in the total area indicates an increasing number or size of tasks moving through the workflow over the observed time period.
Figure 4.19: Sample CFD (Source: Vabro)
Figure 4-19 above shows a Vabro dashboard displaying a Cumulative Flow Diagram (CFD), tracking task progress across different statuses.