What is the biggest challenge using Kanban?
As you know it is possible to implement Kanban the most difficult task is to set the right WIP (Work in Process). It means you need to put limit of your work in each column of your Kanban board.
This image was extracted from brodzinski.com
Many people think there a formula or a way to calculate the most appropriate number to put as limit in each step of your workflow. I am so sorry but there is nothing like that. However, you can use this amazing tool to realise about the mechanism behind WIP.
You only need to press “Start” and you will be playing with the original configuration (development with a limit of 3, Test equal to 2 and Deploy equal to 1) of the game (or activity if you want to call it).
Then as far as you realised that you need to feed your board you have to “Add cards” to keep playing.
Next you should let the software working alone and after a while put on “Pause” the game and check the Cumulative Flow Diagram (it is called CFD in many papers). From there you can check what was happening with your WIPs. If there graph shows a lot of work in Ready and a few in Live (Black is for Ready and Green is for Live (think on it as Production) you need to change your WIPs in order to obtain more Green (Live) and less Black (work in Ready).
One of the best WIP combination that I have got playing the game with many clients is the following: Development with WIP equal to 2, Test with a WIP set to 1 and Deploy with a WIP equal to 1. As far as you realised that the main idea of Lean is “one piece of flow” so it is not unusual to observer this behaviour.
To sum it up, if you use Kanban in your company I strongly recommend to you to observe very carefully the value of each WIP, record the metrics of your CFD to see what is the biggest value in that graph (Production or Done means good).
If you want to chat about this amazing topic don’t hesitate to reach me at twitter (@metlucero) or Skype (metlucero).