[HN Gopher] Beer distribution game
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Beer distribution game
Author : aniham
Score : 181 points
Date : 2020-03-23 12:23 UTC (10 hours ago)
(HTM) web link (en.wikipedia.org)
(TXT) w3m dump (en.wikipedia.org)
| xwdv wrote:
| I've never understood how you win the beer distribution game,
| people only ever talk about the effects on the supply chain it
| seems. But how do you mitigate?
| Alex3917 wrote:
| Basically just keep producing the same amount of product
| regardless of the amount of demand you're seeing.
| hef19898 wrote:
| If that turns out to be th solution, the game was played
| based on wrong assumptions. You have to measure
| inventorylevels as well, the solution is to define, across
| perticipants, the amount that has to be produced based on
| customer demand (simulated by the trainer/ facilitator).
| [deleted]
| hef19898 wrote:
| Communication, as soon as people are allowed to exchange
| information, results get a lot better. Teams can start
| planning, based on real customer demand,backlogs and so on.
| This changes everything.
| fsckboy wrote:
| which makes perfect sense because among the assumptions of
| free market economics which are required to make the
| invisible hand do its work is "perfect information": buyers
| and sellers share perfect information about conditions,
| costs, markets, supply, demand, etc.
|
| and still there will be bullwhips because the future contains
| uncertainties like "when is the next coronavirus outbreak?"
|
| Silicon Valley operates on secrets (what do Google Amazon and
| Facebook do with your data? anything that is not simply
| further stacking the deck against you?) the elimination of
| which is the direction reform minded people should go with
| regulations.
| kmc22 wrote:
| Played this game in undergrad and this was my exact
| experience.
| sdenton4 wrote:
| The Kobayashi Maru of business school...
| pclmulqdq wrote:
| I wrote a paper on what we thought was the optimal strategy for
| the beer game. My team won a beer game session run at the
| system dynamics society conference about 10 years ago.
|
| 1. Push all the inventory to the end of the supply chain (the
| retailer).
|
| 2. Run the inside of the supply chain on a "pass-through"
| strategy - order exactly what is known to be coming down the
| supply chain on that turn.
|
| 3. Use a control algorithm based on the outflows from the
| retailer to control production at the factory (the factory
| player has to watch the retailer's inventory closely). The best
| parameters for the control system depend on the exact demand
| deck.
| hef19898 wrote:
| Which is exactly what modern supply chain management tries to
| do. On a more complex level so, but the basic idea is the
| same.
| Tade0 wrote:
| This reminds me of a cooperative board game named Space Alert:
|
| https://boardgamegeek.com/boardgame/38453/space-alert
|
| Players are crew members of a 6-room ship, equipped with weapons
| and generators supplying power (ammo) - all operated manually.
|
| Each round consists of a planning and execution phase. During the
| former players listen to a pre-recorded track of incoming threats
| and declare their actions.
|
| In the latter phase the threats start to arrive and the
| previously planned actions are executed.
|
| The difficulty here is that the planning phase is timed, so the
| team has to communicate efficiently.
|
| A single bad decision of a single player may doom the whole team,
| especially that players can and will get in the way of each
| other.
|
| I remember doing just that - instead of going to the generator,
| spending a unit of fuel to charge it and distributing power to
| the turrets I picked the wrong decision card which moved me back
| from where I started, so my pawn was pressing the right buttons,
| but in the wrong room.
|
| To make matters worse on my way back I got in the way of my
| teammate(and informal captain) and prevented him from recharging
| the generator later, which was important, because our turretwoman
| was supposed to be firing all the time.
|
| The aliens destroyed that part of the ship killing her and
| leaving us defenseless.
| tnorthcutt wrote:
| I found this web based version: https://beergameapp.com/
| steerablesafe wrote:
| Even when no communication is allowed during the game, some kind
| of PID control could make the supply chain stable.
| oehpr wrote:
| It's funny you should mention that, because most PID
| configurations are not very stable. Once you introduce the
| Integral and the Derivative, if you're not careful that PID
| will oscillate into the stratosphere.
|
| In fact, I'd say that PID's that are functioning most
| efficiently are very nearly tuned to the point of oscillating.
| Even worse is the kinds of adjustments you have to make to
| PID's when there is significant lag between their inputs and
| outputs.
| rcxdude wrote:
| Indeed. Control loops are generally limited by the bandwidth
| of the system they are controlling, and lag in the system
| limits the bandwidth you can achieve. Trying to get a PID
| loop to move a system faster than that system's bandwidth
| will just create oscillations, and the more tightly the PID
| is tuned the worse its behaviour when exposed to shocks
| (especially when the system becomes significantly non-linear
| in the process).
|
| You can extract more performance out of a system by having a
| very good predictive model of it and measuring its inputs:
| This can really improve how you drive the system but it's
| much more difficult to achieve, and you're still limited by
| how quickly information moves through the system in terms of
| how you can react.
| _0ffh wrote:
| Yeah, I think that's a much more promising approach. Have a
| good model, use it to build an observer, now you can
| control based on the state of your simulated system.
| hef19898 wrote:
| You described Supply Chains pretty well, I think!
| jacques_chester wrote:
| The Beer Distribution Game is one of the touchstone examples
| for introductions to Systems Dynamics, a field pioneered at MIT
| with direct roots in control theory. PID controllers are not
| news in that part of the world.
|
| A major insight of the field is that lags due to accumulation
| create wildly unexpected behaviours in systems that humans try
| to control. Many automated systems struggle too.
| tsumnia wrote:
| Here's an old Flash game that you can play to see how it works:
|
| https://forio.com/simulate/mbean/near-beer-game/run/
| somebodynew wrote:
| What do you use to run embedded Flash these days? I haven't
| used Flash since all of the major browsers started blocking it.
| tsumnia wrote:
| You are re-enable it in Chrome, that's what I've done in the
| past.
| yawgmoth wrote:
| LLamasoft/Opex have one, you can play it!
|
| https://beergame.opexanalytics.com/#/
| https://opexanalytics.com/beergame/
| pinky1417 wrote:
| I played this game during orientation when I started my MBA at
| MIT Sloan (the game was originated at Sloan). In my second year,
| I facilitated the game.
|
| The most eye-opening thing for me was that a good quarter of
| students were frustrated and surprised by the bullwhip effect.
| I'd guess the general population would be even less understanding
| of a bullwhip effect. I think that help explains why it seems so
| many people don't understand why it's difficult, even for the
| U.S. federal government, to create more supply of hand sanitizer,
| respirators, etc.
|
| P.S. To be clear: I'm not suggesting the federal government isn't
| to blame for a lack of supply - we should have had a larger
| strategic reserve of pandemic mitigating supplies prior to the
| crisis, if only due to the risk of biological weapons (those
| preparations would have been just about as useful in a non-human-
| caused pandemic like COVID-19). Nor am I saying the government
| can't do more right now. The Beer Distribution Game merely helps
| partially demonstrate why manufacturers, suppliers, and the
| government (especially if they themselves understand the bullwhip
| effect!) don't instantly will pandemic supplies into existence.
| thechao wrote:
| The Wikipedia article only has a cursory overview, but I'm
| strongly reminded of the coordination issues I saw in
| _software_ rasterizer pipelines, with respect to queuing, load-
| balancing, and buffering. A lot of novice engineers who
| approach parallel SW rasterization are surprised when they see
| production systems & the "buffers" between phases are "one
| deep" (say, 1024 samples; 128x16 vertices; etc). Explaining why
| this is both: 1. optimal; and, 2. the stated design goal, is
| always the first task when onboarding them. (Briefly: we size
| the phases so they've got soft real time guarantees, so that
| the pipeline is always "smooth"; in a SW rasterizer, you can
| never "get ahead", so regardless of your buffering size, the
| buffer is always "empty" or "full"--never "in between". Before
| starting work, you check if your downstream buffer is full, or
| if your upstream buffer is empty; if so: do something else!
| That sort of system can be modeled with a buffer of size==1!)
| im3w1l wrote:
| Hand sanitizer is a simple product. People could make it at
| home if you legalized moonshine.
| hef19898 wrote:
| It's the same for supply chain professionals.Not sure howyou
| played and facilitated it,but the versionI had had a first
| round with no communication. During which _all_ teams, also
| those consisting of seasoned supply chain people, just fell
| victim to the bullwhip effect. everytime. Me to, and I knew the
| effect _and_ the rules of the game.
|
| A nasty thing, this bullwhip effect.
| Scoundreller wrote:
| Heh, in my days working in a pharmacy (hybrid service & product
| world), it was amusing whenever prescribers (service-oriented)
| felt we could work harder to create stock.
|
| Sure, I'll just work a few extra hours to grow the crop of
| plants we extract this drug from.
|
| Or build some more vats that we brew this drug in.
| CoffeeDregs wrote:
| Ha! Same here. Almost started an IAP session with Senge to let
| people play it multiple times (with varying demand curves)
| because it seemed to have a lot of exploration left...
| speleding wrote:
| Wow, I didn't realise there are so many Sloanies here. I
| attended a class where Jay Forrester himself came in to teach
| for a day (in 1998), in his eighties. Impressive man, yet so
| humble.
| Veedrac wrote:
| This doesn't actually demonstrate that it's difficult, just
| that it's _expensive_. If the government is willing to eat any
| sunk cost from oversupply, everything becomes predictable. In
| the case of COVID, it 's hard to imagine any quantity of hand
| sanitizer and respirators doing more damage than the harm they
| prevent.
| hef19898 wrote:
| For one product, yes. For multiple product sharing resources
| it gets difficult as over production for one product might
| directly result in shortages for another.
|
| Production hand sanitizer and masks and such is being ramped
| up, now that Chinese factories are slowly going back online.
| Things like that take some time, so.
| Sherl wrote:
| >expensive
|
| you deal those with scenario planning, which might be the
| sole responsibility of pandemic unit. We use casual loop
| diagrams to understand effects when math cant be drawn out on
| abstract problems.
|
| Its insanely expensive to satisfy 99% populations requirement
| versus 95% of populations requirement but when that happens
| and if the consequence are severe we manage those supply
| chains with redundancy and the costs are absorbed with other
| players. Sure, it would profitable to operate without this
| but my understanding is when this sh*t hits everything falls.
|
| $15 billion savings in 2018 resulted in $12 trillion being
| wiped out in two weeks.
|
| >https://foreignpolicy.com/2020/01/31/coronavirus-china-
| trump...
|
| >https://markets.businessinsider.com/news/stocks/stock-
| market...
| mindcrime wrote:
| I first learned about this from reading Peter Senge's _The Fifth
| Discipline_. If you 're interested in this sort of thing, TFD is
| a worthy read.
|
| https://en.wikipedia.org/wiki/The_Fifth_Discipline
|
| https://www.amazon.com/Fifth-Discipline-Practice-Learning-Or...
| jacques_chester wrote:
| I strongly disagree. Senge's book is hand-wavy, includes acres
| of unactionable fluff and -- this irks me the most --
| introduces causal loop diagrams but fails to introduce stock-
| and-flow diagrams.
|
| Causal loop diagrams are basically toys, useful only during
| initial hypothesis formation. You need a stock-and-flow model
| to actually test and elaborate your hypothesis.
|
| The best all-round introductory book I have read in this area
| is still Sterman's _Business Dynamics_. 1st edition hardbacks
| are out of print, but there are second-hand copies and also
| cheap international editions around. A 2nd edition is expected
| next year.
| leetrout wrote:
| When I was working at UNC I tried to get us to make the beer game
| in VR for the business school. You would actually see the empty
| shelves and then the overstocked warehouse in VR to understand
| the physical constraints of the supply chain and the issues with
| the bullwhip effect.
|
| Could easily be updated to the N95 mask game. Especially given
| what I was reading about melt blown production lines capacity and
| initial install costs.
| hef19898 wrote:
| I adopted it once for aircraft maintenance. Still pen and
| paper, but the session was hilarious! Especially as I played it
| with people directly and indirectly involved with aircraft
| maintenance for the army. The second round was the real eye
| opener, so.
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