The key to Kanban is the WiP limits

Recently, I ran a session of “The ship game” that was created by @klausleopold (read up more about it in my earlier blog from LAST conference). During that session, a couple of the attendees looked to me disbelievingly as they saw lead times halved. The look they gave me was “what kind of trick is this” as if I waved some kind of magic wand and magically sped everything up. The answer in the end was that there was no special magic, just the use of Work in Process limits.

Some teams experience lead times halving, some experience even greater improvements. What this group also found that they also had slack in the system when they introduced WiP limits – they were actually not working as hard and they were achieving better results compared to when they didn’t have WiP limits. To me this really highlights one of the key parts of Kanban is really the WiP limit.

Many people have the misconception that “the Kanban” is just the board. So many times, I’ve heard “we’ve got a board so we’re doing Kanban”. Although a board can be useful, you’re really not getting the full benefits out of Kanban – you really need to start limiting WiP to get the benefits. So much so, that I distinguish between the two – now I refer to “the Kanban” as the slot created by the WiP limit that allows you to pull new work in. I refer to the Board as simply the “Visual Management Board”. I really don’t consider it “Kanban” for knowledge work without the use of WiP limits (see for more details on different kinds of WiP limit implementations).  

The WiP limit is important because it:

  • Allows you to see the capacity available
  • Creates focus to avoid task switching overheads
  • Prevents you from overburdening teams by pushing too much work into the system
  • Stabilises the system such that you can get meaningful lead time metrics
  • Catalyses change by stressing the system (as opposed to the people in the system)
  • Creates slack to allow improvement opportunities to take place

Sometimes it can be hard to introduce this and it certainly may seem counterintuitive when you start, but if you can stick to it, you will get many benefits like those mentioned above. So, please help your team, your customers and ultimately your organisation become more successful by implementing this small change.

If you want to find out more about how to implement a real Kanban system, please check out the upcoming Kanban System Design courses.