# Cycle time Cycle time is the elapsed time between when work on an item started and when it finished. The Kanban Guide lists it as one of four flow measures, next to work in progress, throughput and work item age. It differs from [[Lead time]], which starts earlier: when the item is requested or committed to, not when someone actually starts on it. Lead time is always at least as long as cycle time, and the gap between them is time spent waiting in a queue. Cycle time is useful because it is simple, it is based on what actually happened rather than on estimates, and it connects to the other flow measures through [[Little's Law]]: with the same throughput, more work in progress means longer cycle times. Looking at the distribution rather than the average gives honest forecasts ("85% of my tasks finish within six days"), which is a form of [[Reference class forecasting]] built from your own history. Two cautions. Teams must agree where "started" and "finished" are on the board, otherwise numbers can't be compared. And once cycle time becomes a target, people game it, by splitting work artificially or closing items early ([[Goodhart's Law]]). ## References - Vacanti, D., & Coleman, Y. (2025). The Kanban Guide. https://kanbanguides.org/english/ - Little, J. D. C. (2011). Little's Law as viewed on its 50th anniversary. Operations Research, 59(3), 536-549. https://doi.org/10.1287/opre.1110.0940 - https://concepts.dsebastien.net/concept/cycle-time/ ## Related - [[Lead time]] - [[Little's Law]] - [[Work In Progress (WIP)]] - [[Limit Work In Progress]] - [[Kanban Methodology]] - [[Kanban Boards]] - [[Goodhart's Law]] - [[Reference class forecasting]]