A drastic title, but I really mean it. Some people have a fit when I say that you should limit the work in a Kanban system. The notion of limiting them, and the work, leaves an unpleasant aftertaste. At the implementation level, it sounds like, “You think I’m not capable of doing two things at once?” At higher levels, for instance in portfolio management, it sounds like, “We are rejecting customer orders.”
In the world of working effectively, WIP limits are a core element. Their purpose is to simply prevent you from getting bogged down. This bogging down is most apparent when the only thing being discussed is starting initiatives, proposals and projects. Meanwhile, we know multitasking is a myth and companies are not successful because they start as many projects as possible, but rather when they finish as many projects as possible.
Nothing can fly where everything lands
Here’s the thing: We do not want to restrict or constrain work with WIP limits. Rather, we want to get to the point where arrival and departure rates in the system are nearly equal. I like to compare this to an airport: When there are more airplanes landing than taking off, the entire area will be piled up with airplanes in very short order. It is absolutely logical that an airport has a certain capacity (WIP limit) and that arrivals and departures are planned based on this capacity (starting and completing work). If the airport is at capacity, airplanes must depart (work must be completed) before the next airplanes can land (new work can be started).
Most importantly, limiting the amount of work in a work system is a means to an end. There should not be more work started than can be finished. To prevent the system from becoming clogged, there can only be a certain amount of active work, and this amount is represented by the WIP limit. Even though my inherent enthusiasm for WIP limits will probably never waver, and from every possible practical and theoretical point of view they simply make sense, I find myself more and more often trying to avoid the term “limit”. It prompts many people to make an incorrect association. But I am baffled at the moment how to phrase WIP limits differently.
Does anyone have an idea? I would be thankful for any suggestions.