# The lean dice game

Often lean games use different materials to simulate a production. Products have to be made for example from Lego or Stickle bricks. Or real products such as  flash lights, electrical plugs, or pens are used. One disadvantage of these simulation is that getting the material can be quite costly.  Therefore let me introduce a lean simulation game where you only need a couple of dices!

The game can be used to learn things such as pull and push, flow, 7+1 waste, 5S, Kanban, line balancing, ...  In other words you can teach all of the lean concepts that you could also teach with an off the shelve lean game kit.

## Necessities

• 100 dices, you can buy a pack of 100 dices for a few bucks

or Alternatively

• 3 to 5 dices

If you do not want to spend any money and have some game boards at home you could play the game with 3 to 5 dices,, but then not all lean concepts can be explained as easily.

## Rules

you can play this game with 5 to 10 players. One person will be the handler that transports the dices from station to station. The other persons represent a production step.  The person who represents step 1 has to turn all dices so that number 1 is at the top of the dice.  The person who represents step 2 has to turn all dices so that number 2 is at the top of the dice. And so on. If you play with more than 7 players (6 process steps and a handler), player 8 will turn the dices again to number 1. And so on. You could also add an extra handler if you want.

In order to have a bottleneck in the simulation. One of the players has to also make certain that the number facing away from him is also the same. Which player this is depends on the number of players:

• 5 players: step 3 has to make certain number 3 is on top and number 6 is facing away from him
• 6 players: step 3 has to make certain number 3 is on top and number 6 is facing away from him
• 7 players: step 4 has to make certain number 4 is on top and number 6 is facing away from him
• 8 players: step 4 has to make certain number 4 is on top and number 6 is facing away from him
• 9 players: step 5 has to make certain number 5 is on top and number 6 is facing away from him
• 10 players: step 5 has to make certain number 5 is on top and number 6 is facing away from him

## Rounds

For the first round you have to place the persons in a random order/location. Only the handler is allowed to move the dices from one workstation to another.  In other words there will be a lot of waste due to transport. The benefits of making a spaghetti diagram could be showed here after the first round!

A batch size of 5 dices is used. Each step must first flip all dices before calling the handler who passes the dices to the next station.

After each round the team can do some optimizations. Personally I like to give them targets per round rather than letting them implement all changes at once.  For example:

• round 1 - reference round: Current states of the production process. You can discuss how to map the current status (for example flow charts or value stream maps) and why it is important to map the current status (baseline for further improvements). You can use this further in the simulation to discuss changes and adapt the map (current vs future mapping)
• round 2 - eliminate handler: You can talk about the 7+1 wastes and how to visualize transport with a spaghetti diagram. Also 5S could be discussed. How can the workstations be organized efficiently? For example, how would you define the Work in Progress (WIP) locations.
• round 3 - reduce batch size: You can talk about one piece flow and the effect on the lead time. Furthermore you will see how WIP can be influenced by the batch size.
• round 4 - implement pull: You can talk about the 5 lean principles. The benefits of pull vs push can be discussed. Also Kanban can be introduced in this round.
• round 5 - line balancing: You can explain cycle and takt times and create a graph to visualize the unbalance. You can explain the theory of constraints (bottlenecks).

Each round is one minute. Depending on the skills of your participants you could decide to have rounds of 90 seconds or 2 minutes.  Young people tend to be quicker than older people.

Make sure that you time how long it takes for the first dice to go through all the steps. This time should improve after each round.  In the first round you have to measure the lead time yourself. In the next rounds you could give this task to the handler. He can also measure the cycle times per person. These times can be used during the line balancing round.

## Scoring

The goal is to score at the end of the round as many point as possible. For  each finished dice you get points. The points are equal to the number which is on top of the dice. So if you have 4 production steps (step 4 has to turn the dices to have the number 4 on the top) and you have 20 dices finished, you get 80 (20x4) points.  If you have 5 production steps and you have 15 dices finished, you get 75 (15x5)  points.

But, you also have to subtract the work in progress (WIP). The value of the WIP is equal to sum of the numbers on top of the dices. For example if there are 5 dices between step 1 and 2. The WIP is 5. If there are also 10 dices between step 2 and 3 the WIP is 20 (10 x2).  The total WIP is 25. We have to subtract in this case 25 from the score of the finished dices to have the end score.

Please note that the handler will probably throw the dices into the next workstation. This will cause them to not lying like the previous step has laid them. This is okay. You can just count them If like they were lying in the right way.

## Learning points

There are several learning points which can be taken away from this simulation:

• The link between batch size and lead time will become clear. Products are delivered quicker when smaller batches or one piece flow is used.
• The work in progress is reduced when using smaller batch sizes or one piece flow. This Reduces the cost when there is a drop in demand or warranty issue where all products in stock have to be scrapped or reworked. Also working with small batches  reduces the impact when there is a customer change
• Introducing Kanban will limited the work in progress and free up capital.
• By introducing the 5 lean principles you will reduce waste and increase profit

Have fun playing this game!