If work is waiting 90% of the time, then only work is ever in progress for 10% of time. Does this impediment to flow create naturally occurring work-in-progress limits?
Work can be waiting for all kinds of reasons. It can be waiting for approval, waiting for someone to become free to pick it up, moving between roles.
Reducing the time work is waiting is one way to reduce the time it takes to get value from that work. But sometimes that isn’t possible, so it’s necessary to work without applied work-in-progress limits.
How we define ‘in progress’ matters. Is work in progress if it has started but isn’t finished? Or is work in progress if it has been started, is actively being worked on, but isn’t finished? In which case, work that isn’t being actively worked on is ‘work in waiting’.
One perspective sees time spent ‘in waiting’ as waste. If that work was finished sooner, then more value would be realised from it.
But, having work ‘in waiting’ creates a natural limit to work-in-progress.