Last month I had the opportunity to provide an Agile and Scrum class to a private client. We had a great day learning and having fun. At one point a clever developer threw a twist into one of the exercises that had me worried.

Let me set the stage a bit.

The Penny Game

The Penny Game is a fun way to help people experience the effects large and small batch sizes and other lean ideas.  The basic action of the game has the participants flipping and passing pennies from one person to the next.

Rather than explain it all here I will point you to the web.  The simplest version and description I quickly found was on the Crisp blog.  If you are not familiar with the game, read the description there to better understand what I describe below.

The Clever Twist

The first “Worker” in the game was a programmer, a clever programmer as it turns out.  The first batch size was 20 pennies. I said “Go” and he proceeded to make a heads up stack of all his pennies.  A single stack!  He then carefully flipped over the entire stack at once, instead of flipping them one at a time.  He took a while to do this, as you may imagine, so I was not worried yet.

Then, he carefully handed the entire stack to the next person, who flipped all 20 pennies over at once, as a stack! Now I was worried because each successive “Worker” did the same, each saving a lot of time for a large batch size.  I worried that the point of the game would be lost since the numbers were not coming out as expected.  I told the class of my surprise and worry. I told them not to stop, let’s run the experiment!

The Results

The usual results of this game show that smaller batch size results in significantly faster delivery to the customer.  What do you think happened in this case, with flipping happening in one careful motion?

Surprise! The results still came out as expected. Flipping and passing the pennies one at a time (a batch size of one) was still faster for the customer and overal completion than flipping an entire multi-penny batch all at once.  The delivery speed improvement was not as dramatic, but it still held true.

Our discussion after the exercise was quite interesting. And I was grinning widely that my “risk” at letting the game proceed paid off in making the game more interesting.