Classroom slides
36-week game · inventory $0.50 · backlog $1.00 · instructor guide
Briefing
The Beer Game
A supply chain simulation. Four roles, one product, 36 weeks.
You make exactly one decision each week: how much to order.
Briefing
Welcome to the Beer Game
You're about to play the MIT Beer Game, one of the most famous simulations in business education. It teaches how supply chains work — and how they can go terribly wrong.
The game simulates a simple supply chain for beer, with four roles: Retailer, Wholesaler, Distributor, and Factory.
Briefing
The four roles
Each role manages one stage of the chain. Beer flows downstream toward the customer; orders flow upstream toward the factory.
Sells beer to the end customer, and is the only role that sees real customer demand. Fills customer orders from inventory and orders more from the Wholesaler.
Supplies the Retailer. Never sees the customer — only the Retailer's orders. Fills them from inventory and orders more from the Distributor.
Supplies the Wholesaler. Two steps from real demand, where delays start compounding. Fills the Wholesaler's orders and orders more from the Factory.
Brews the beer. Furthest from the customer, so demand signals arrive latest and most distorted. Fills the Distributor's orders and schedules new production.
Beer flows → toward the customer. Orders flow ← toward the factory.
Briefing
How each week works
- 1Receive shipments — Beer that was shipped to you arrives in your inventory.
- 2See incoming order — Your downstream customer has placed an order.
- 3Fill orders — You ship as much as you can from your inventory. Anything you can't fill becomes backlog.
- 4Place your order — Decide how much to order from your supplier. (The Factory has none: it schedules production instead.)
- 5Costs accrue — You pay $0.50/case/week for inventory and $1.00/case/week for backlog.
Briefing
Key concepts
Cases you have on hand. Costs $0.50/case/week to hold.
Orders you couldn't fill. Costs $1.00/case/week. These carry over until you have enough inventory to ship.
Orders and shipments take time to arrive. There's a delay between ordering and receiving — 3 weeks from placing an order to the beer landing in your inventory — and this is crucial!
Briefing
Important rules
During the game, you won't see what the other roles are doing. You only know your own inventory, backlog, and the orders you receive. This is by design — it's what creates the learning experience.
Real supply chain partners mostly communicate through purchase orders alone. So do you.
Your goal: minimize your total cost over the 36-week game. There's no profit to chase — every player buys and sells at the same price. The only thing that separates a good result from a bad one is how much you spend on inventory holding and backlog penalties. The winning strategy is the one that wastes the least.
Briefing
What it costs
Backlog costs 2× as much as inventory, and a backlog never goes away on its own — it waits until you can ship it. But inventory you don't need costs you every single week. Lowest total cost across all 36 weeks wins.
Briefing
What you'll see
Your screen each week: inventory, backlog, the order that just came in, what's in transit — and one box to fill.
Briefing
Ready to play
- 1Open the link (or scan the code) on any laptop, tablet, or phone.
- 2Enter your name. No account needed.
- 3Wait for your role. The game starts when every seat is filled.
- 4Sit apart from your supply chain — and no talking about orders.
Play
Stop here. Play the game.
The next slides are the debrief — they give away the answer.
Come back after the final week, with the analytics open.
Debrief
What just happened?
Everyone tried to do a good job. Look at the order chart.
Before we look at why — a few questions.
Question 1
Who or what do you blame for your costs?
Be honest. Name names.
Question 2
What did you think customer demand was doing?
Every role: what did you think the customer was doing?
Question 3 · The reveal
How many times did customer demand actually change?
Once. It was 4 cases a week, rising to 8 in week 5, then flat for the rest of the game.
Customer demand, week by week. That's the whole disturbance.
Question 4
Why did you order more than you needed?
What were you afraid of?
Question 5
What one piece of information would have changed your decisions most?
If you could have seen one more number each week — which?
Question 6
Which role paid the most, and why is that not a coincidence?
Look at the cost by role. Who paid most?
Question 7
If you replayed with the exact same rules, what would you do differently?
Same rules, same delays, no talking. What changes?
Question 8
What would change if the four of you could talk?
What would you tell each other — and would you believe it?
Question 9
Where have you seen this pattern in real life?
Shortages, boom-and-bust ordering, empty shelves. Where?
Question 10
Everyone acted rationally. So why did the system fail?
Nobody was foolish. So what was?
Debrief
Anatomy of a bullwhip
Inventory drains before new stock arrives, because orders take weeks to become deliveries.
Backlog builds, panic sets in, and each stage orders more than it needs — while its earlier orders are still in transit.
The panic orders all arrive at once. Inventory piles up across the chain just as everyone stops ordering.
Stages sit on excess stock and order almost nothing while it burns down. The swings shrink, but rarely settle.
Debrief
Key takeaways
Delays plus local information produce oscillation no matter who is playing. The villain is the system, not a person.
Every stage upstream forecasts from the orders below it, and each stage adds its own distortion. Amplification is the default.
Most of the damage comes from ordering against what has arrived and forgetting what is already on the way.
Sharing real customer demand does more than any ordering rule. That is why point-of-sale sharing, CPFR and VMI exist.
Debrief
How real supply chains fight it
Let every stage see point-of-sale demand instead of forecasting from the orders below.
Every week of delay is a week of guessing. Faster order and shipping cycles shrink the swings.
Batching turns steady consumption into lumpy orders upstream.
Promotions cause forward-buying: a boom the chain sees, followed by a bust it doesn't understand.
Order against inventory position — on hand plus in transit — not just what's on the shelf.
Debrief
Everyone acted rationally. The system still failed.
Local rationality + delays + limited information = global dysfunction.
Go back to the people you blamed in question one. The villain was the structure all along.
Match these slides to a game by adding ?weeks=10&demand=4,8@5 to the address — the session lobby does this for you. The briefing never mentions the demand pattern; the debrief reveals it.