Monday, May 16, 2011

A Whole Slew of Dice Games

This Goldratt-inspired dice game demonstrates the theory of constraints and interdependency. The WSU website created by James Holt gives very clear instructions on how to run your own dice game, including all the details for each iteration and what the expected results should be.

Last year I posted about MIT's version of this game, called the Variability Simulation. This dice game is a version of the same game, but includes several more in depth variations.

It's not just one dice game. By switching a few things, tweaking this or that, different processes can be emulated.

The Basic Dice Game:
  • Push System
  • 1 Die per operator
  • Each operator rolls their die and moves the equivalent number of tokens to the next station.
What happens? 

On average, everyone moves the same number of tokens. It's a statistical certainty. Ha. Just make sure you roll a million times! But the variations in dice rolling cause a ton of inefficiencies in the process.

When a worker rolls low, he can't move all his tokens and builds up a stock of inventory, becoming a bottleneck. Alternately, when a worker rolls high, he might not have tokens to move and wastes this high roll.

What do you learn?

Interdependency. It doesn't matter if one worker is very efficient, because the previous process may be starving him of parts. The dice game shows how each process is linked and dependent on the processes before and after it. The improvement focus should be on the entire value stream, not just working with each individual process.

Best quote from the rules:

"While cheating is fun, it lessens the learning for this first time. They can cheat later."

Variations on the basic dice game:

The website describes no less than 5 different versions of the dice game, that progressively become more complicated and illustrate different methods.

  1. Push game variation with preloaded inventory.
  2. Pull or kanban version where workers roll from the final process back to the first. 
  3. Theory of Constraints version where the first station is pull and the rest are push.
  4. Assembly model where multiple workers feed a single station, instead of one linear flow.
  5. And finally a complex assembly or routing model, where infinite possibilities exist to model your own process with multiple workers dependent on each other. Good luck!

Has anyone tried running the Dice Game or some version of it? What was your experience?

Link to the detailed instructions for running your own dice game is here:

I've added this page to my huge list of free Lean games.

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