Bottleneck Busters Blog

In some of the forums I have been following, there has a noticeable lack of support for simulation as either a manufacturing tool or as a TOC tool.  But my experience with simulation has shown it to be a valuable asset.  Over the next few sessions, I’ve decided to share my experiences with simulation and see what kind of response I get.  The first area I want to talk about it the use of simulation games to help sell TOC and change the current paradigm of the customer.

Why Games?

I have found games to be an effective way to get past the first two layers in the Five (or is it 6? 9?) Layers of Resistance that I learned in Jonah school.  These first two layers are:

Layer 1
Raising problems having one thing in common – it’s out of our hands: vendors do not always deliver, clients change their minds at the last minute, workers at not properly trained...

Layer 2
Arguing that the proposed solution cannot possibly yield the desired outcome.

Using the games described below helped demonstrate that our customers can impact the problem, and the proposed solution will yield the desired outcome.

Production Games
I’ve always felt that using simple simulations as games, as is done in most TOC throughput courses I have sat through, is a great use of the tool.  A simple model is a safe place to challenge the paradigm that you have about how to run a plant.  Play the game once with your methods, and then play it again with mine, and we’ll see which method generates the most profit. There are no excuses and no one else to blame, and if you think you got unlucky, then play the game again. 

At GM, we developed a simple game that uses C-More to help sell the tool and the Throughput Improvement Process.  It was Excel based, and used C-More as the simulation engine.  Players had all the data they could possibly need, and had to pick which workstation and which metric (downtime, speed, failure frequency, etc.) that they wanted to improve. 

They generally did fine in the beginning, when the bottleneck was obvious and the data clearly showed its location.  But after a few rounds, the fixes started to have no impact on throughput, meaning they had chosen the wrong bottleneck to improve (or, in some cases, the wrong metric to improve on the bottleneck). 

In the second round, they had access to the bottleneck report as generated by C-More.  If we had time, we let them “test” each one of the possible fixes, to help them decide which fix to install.  Their throughput rates at the end of this round were significantly higher, and we made the point to calculate the difference in revenue (assuming the product was in demand) between their method and using C-More.  Finally, we compared that increased revenue to the combined salaries in the room! 

Design Games
We played a slightly different version of the production game to help engineers and process managers change their view about how to design a plant.  In the previous version, the players where not allowed to add a workstation or change the number of buffers. In the design game, the players are not allowed to change the downtime characteristics of the machine, but can choose from five different types of machines for any process, have as many machines as they want, have any buffer size they want, can design the configuration of the line, etc.  Again, we play it first using their methods, which is usually very chaotic.  When we teach the class to a room full of two-player teams, we rarely get consensus on choosing one type of machine for any process step.   Results are all over the board, but in the end, no design meets the original criteria for success.

The second time, we use TOC methods to select which machines to use, the number, the buffer sizes, etc.  Surprisingly to the lean folks, the design comes out with less investment and higher throughput.  The resulting change in ROI is impressive, and usually results in a call for using simulation to help design the next set of manufacturing processes.  Once again, we compare the difference in results for this simple game to the combined salaries in the room, to make sure they understand the magnitude of the problem and the impact of the solution.

Finally, having only starting doing critical chain work, I am surprised that I have not run across a simple simulation game for CC that does the above.  I have seen a few simple tools that demonstrate the difference, and perhaps that is enough.  Or perhaps there is not a perceived need for a game to change the paradigm of the customer.  Or, there just might be one out there that I don’t know about. It’s something I would like to explore further.

Kevin