Cumulative flow diagram

A cumulative flow diagram is a tool used in queuing theory. It is an area graph that depicts the quantity of work in a given state, showing arrivals, time in queue, quantity in queue, and departure.

Cumulative flow diagrams are seen in the literature of agile software development and lean product development. They are also seen in transportation.

Another term is "cumulative input-output diagram". The term "Newell curve" is also used, in reference to Gordon F. Newell. It is not known if Newell originated the curve.