“Flappy Birds” is a Lean game. It delivers value (fun) to its target group (casual gamers) with minimum effort (game play and production cost) at a price accepted by the market (zero, if you do not count in the ads). But this is only the obvious observation.
That metaphor includes production rates, production control, customer demand, and inventory waste.
If you have not played it yet, you may want to give it a try. Links to the game can be found at the end of this post.
OK, here is how the game is a metaphor for a factory. In this game, you have a bird that sinks if you do nothing and rises for a short time when you give a signal by tapping. The aim is to fly through gaps in columns that are at the top and bottom of the screen. When you hit a column, the game is over.
- The flight height of the bird can be seen as the amount of goods that is in scope of the process.
- When the bird sinks, the amount of goods sinks because they are sold. The goods leave the simulation scope. The selling rate is the sink rate of the bird.
- When you tap on the screen, you give the signal to produce more goods than the selling rate for an amount of time. If you do not give repeat signals, the production stops.
- The rhythm of tapping is the only means of controlling the whole process.
- The lower columns stand for the amount of goods that can be held in trucks on the road. That is the rolling inventory.
- If you hit a lower column that means you have less goods in total than you have available space on trucks. That means, empty trucks would need to stand on the factory premises or drive around.
- The gap between the lower and the upper column is the buffer space you have in the factory. In that buffer space you can keep a limited amount of inventory that exceeds the space available on trucks.
- The upper columns stand for the total amount of space (trucks and buffer) that is available.
- If you hit an upper column, you produced more goods than you can store. That is over-production.
- There are invisible boundaries between the columns: You can only go higher so far before it is not possible to fly under the next upper column and only so low to go over the next lower column.
- In contrast to factory reality, you know one thing for sure: the demand from customers is predictable. It is defined by the sink rate of the bird when you do not tap. There are no unexpected ebbs in customer demand. That means you only need to adapt to the inventory constraints.
Once you start to play the game you will realize that the rules are very easy to learn but the game is difficult to master. One might say this is not very different from running a stable factory that produces the same goods over the time.
The difficulty comes from the fact that the height of columns is constantly changing. Sometimes you have to fly very low after a high gap and vice versa. Translating that to the factory setting that means you do not have control over your inventory. You also have no control over your rolling inventory, which also stands for transportation waste.
If the columns would have the same height all the time, you quickly would find the right rhythm. Not only that this would be a rhythm, it would also be a takt time. You might soon discover that tapping at a constant rate is the solution, let’s say once a second. In the factory setting that is what you call a constant flow of value.
Whatever you produce, be it pancakes in the kitchen at home, cars in a factory, or patient health in a hospital, you want to achieve a constant flow.
So look around at what you currently do:
Then change something. Maybe you could start with playing the game on your phone or tablet for five minutes. Unfortunately it is not available in the stores right now — but the developer said it will return.
Here are the links for the time being:
Have fun and please do me a favor: Leave a comment. What is your opinion about this thought experiment?
PS: Ryan E. Day from Quality Digest is taking the discussion further: Lean, the Theory of Constraints, and Flappy Bird