Comparison
Flow efficiencyvsWork-in-progress limit
Flow efficiency
the ticket was open for nine days and someone was actively working on it for six hours of that.
The proportion of elapsed time in which work is actually being worked on rather than waiting. It is typically shocking the first time it is measured — figures under twenty percent are normal — and it reframes improvement work entirely, because shaving an hour off active work is pointless when eight days are queueing. It is the number that justifies work-in-progress limits to people who do not want to hear about them.
Full entry →Work-in-progress limit
you were told to finish one of the four things you had started before picking up a fifth.
A cap on how many items may be in flight at once, per person or per team. It feels like a restriction and functions as a throughput improvement, because unfinished work delivers nothing while consuming attention, context and review capacity. It also makes bottlenecks visible immediately: when the limit is hit and nothing can start, the reason is the thing everyone was quietly working around.
Full entry →