Cumulative Flow Diagrams (CFDs) are a useful tool for understanding the progress of a project. They are used in various business contexts, such as software development and project management, to illustrate and analyze the flow of work over time.

CFDs can provide insight into how a project is progressing and can be used to identify potential areas of improvement or to better understand the development process. CFDs are composed of a series of data points that are plotted on a graph. The data points are the number of tasks that have entered or exited the process in a given time frame, and they are typically represented by different colors, such as green and red. The vertical axis of the graph typically shows the number of tasks, while the horizontal axis shows time.

The resulting graph indicates the number of tasks that have been completed, are in progress, or are waiting to be started over time.