The percentage of time where work is done vs. waiting for work to be done. Calculate it by dividing work time by work + wait time.
— Making Work Visible, Second Edition, Dominica Degrandis
Flow Efficiency
4 of our books define this term — and their definitions are worth reading side by side.
the proportion of time flow items actively worked on to the total time elapsed. This can be used to identify inefficiencies such as overly long wait time for particular flow items.
— Project to Product, Mik Kersten
The proportion of active time (or touch time) compared to overall lead time within the value stream, offering a gauge for assessing the stream’s operational efficiency. This metric should be placed in the context of blocks, interruptions, rework, and other detrimental factors affecting performance. It can be refined to emphasize the contribution of direct value-generating activities to the stream’s performance.
— Flow Engineering, Steve Pereira and Andrew Davis
the ratio of active time versus wait time in the total Flow Time
— Four Frameworks for Portfolio Management, in the text
See also Flow · Flow Time · Lead Time · value stream · Wait Time · value stream mapping
Filed under Flow & Lean