Archive for December, 2009

A Kanban Brown Bag Recipe

03/12/2009

Kanban appeals to me, and I have had the privilege to hold a brown bag on it two times in the last weeks. The feedback and especially the discussions it started exceeded my expectations in a very positive way. Therefore, I thought it might be worth sharing my recipe for a Kanban brown bag.


The materials you need:

  • Henrik Kniberg’s Kanban kick-start example. (Thank you very much for sharing this Henrik! It would have taken ages to prepare the brown bag without it)
  • A keyword cheat sheet
  • 20 coins
  • 5 stopwatches (or mobiles)
  • 8 participants + yourself

Step 1: Presentation
Connect your computer to the projector and open Henrik’s kick-start example. Scribble down the following keywords on a flip chart as you explain how they are illustrated with Henrik’s example:

  • Visibility – The Kanban board. Visualize bottlenecks
  • Limit Work In Progress (WIP) – Avoid task-switching. Focus on throughput rather than over-utilizing individuals
  • Pull – You are not allowed to push work down the workflow, you pull work when you are ready and are below WIP limit
  • Flow – A steady flow (all the way from analysis to production), not iterations
  • Cadence – You measure and predict, instead of plan and promise

Assuming you have a basic understanding of Kanban and agree with my selection of keywords, your audience should now have learned the basic concepts of Kanban. To make them fully grasp the value of limiting work in progress the next step is to play a simple game:

Step 2: Play a game
I learned this game at XTC (once again thanks to Henrik Kniberg who facilitated the game at XTC).

Basically you start with four players, and four “managers”, standing behind one player each with their stopwatches ready. The first player gets 20 coins. His job is to flip all 20 coins, then pass them on to the next player, which will then flip all 20, then pass them on etc.. Each manager measures the time, from when his player starts flipping the first coin, until he has flipped all 20. You as a facilitator, should measure the time from the first person flips the first coin, until the last person flips the last coin. The initial scoreboard would look like this:

Batch size Player 1 Player 2 Player 3 Player 4 Total time
20
5
1

The next round, the first person flips 5 coins, passes them on, flips the next 5 etc. Each manager measures the time from his player flips his first coin, until he passes the last coin on. The next person starts flipping the 5 coins as soon as he receives them, passes them on, then starts on the next 5 when available… You as a facilitator, measures the total time. The last round, the first player flips one single coin, passes it on, then flips the next..

If you don’t want to know the typical outcome of the game, stop reading now!

The outcome of the game will most likely look something like this:

Batch size Player 1 Player 2 Player 3 Player 4 Total time
20 9.8 11 13 14 56.4
5 16.7 17 21.5 19 32.6
1 14.9 21 23.1 22.3 26.3

As you can see, the individual times is higher for the smaller batch sizes. However, the total time is much better for the smaller batch sizes.

Batch size Methodology
20 “Waterfall”
5 “Scrum”
1 “Kanban”

I have indicated next to each total time which process the different batch sizes could relate to. Hence, tell your audience that if they want to improve their overall throughput, they should limit their WIP and give Kanban a try 🙂

Thanks again to everyone in the community who have shared their material and knowledge.