Beer Game
2009 10,29 Linkoping University MBA 리더십 과정 수업에서 실제로 진행된 수업내용입니다.
비어게임은 1960년대 MIT의 Jay Forrester교수에 의하여 개발된 게임입니다. 물류의 기본을 익히기 위하여 많은 MBA학교들이 수업과정에 도입하여 진행하고 있습니다. 기본 개념은 간단합니다만 어떠한 일이 발생할지 알지 못한다면 대부분의 경우에서 관리에 실패하는 경우가 많습니다.
비어게임에 대하여 더 알고싶으시다면
http://www.masystem.com/beergame
http://blog.naver.com/jhenna?Redirect=Log&logNo=140058088127
데이타의 수집과 비교를 위한 엑셀파일이 첨부파일로 등록되어 있습니다.
Beer.xls
Report.pdf
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이 게임은 유통과정에서 발생하는 비용발생의 원인에 대하여 파악하기 위한 게임이다. 4명으로 이루어진 팀원은 각각 소매상, 도매상, 물류창고, 공장중 하나를 담당하게 된다.
[고객] – [소매상] – [도매상] – [물류창고] – [공장] – [재료산지]
· 각 팀원은 게임시작 전, 12의 재고를 가지고 있다. · 각 팀원이 주문을 할 경우, 해당 주문이 상위개체로 전달되기까지 2일이 소요되며, 하위개체로의 배송처리에 2일이 소요된다. 따라서 주문건을 배송받기까지 총 4일이 소요된다. · 재고가 모자라서 전량을 배송하지 못한 경우, 다음날 추가로 배송할 수 없으며 손실로 처리된다. · 각 팀원은 게임도중 서로 대화를 나눌 수 없으며, 주문과 배송역시 다른 팀원이 볼 수 없다. · 재고가 모자라서 발생한 손실 : 1개당 $15 · 재고유지비용 : 1개당 $5
게임의 목표 : 재고가 모자라거나 넘치지 않도록 유지한다.
게임방식 : · [고객]으로부터 매일 4~8 의 주문이 랜덤으로 발생한다. · 주문을 접수받은 [소매상]은 주문양을 소비자에게 배송하고 자신의 재고수량과 주문양을 고려하여 적절한 수량을 [도매상]에게 주문한다. · 주문을 접수받은 [도매상]은 주문양을 [소매상]에게 배송하고 자신의 재고수량과 주문양을 고려하여 적절한 수량을 [물류창고]에게 주문한다. · 주문을 접수받은 [물류창고]는 주문양을 [도매상]에게 배송하고 자신의 재고수량과 주문양을 고려하여 적절한 수량을 [공장]에게 주문한다. · 주문을 접수받은 [공장]은 주문양을 [물류창고]에게 배송하고 자신의 재고수량과 주문양을 고려하여 적절한 수량을 생산한다. · 위 과정을 약 60일 반복한다. · 각 팀원은 매일 발생하는 재고와 주문 및 배송량을 기록한다. · 60일의 반복과정을 마친 뒤, 데이터를 비교해본다.
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소비자측에서의 맥주구입은 4~8으로 고정되어 있었다. 따라서 상식적으로 생각해보자면 소매상과 도매상, 물류창고 또한 8 이상의 재고를 유지할 이유가 없었다. 하지만 결과는 어떻게 되었을까?
게임이 끝난 뒤, 게임을 진행한 교수는 각 팀의 공장 담당자들에게 질문하였다.
“소비자측으로부터의 주문이 얼마쯤 되었던 것 같나?”
“글쎄요.. 제가 게임중반에는 평균적으로 150개씩 배달했으니까… 소비자측에서의 주문도 150~200개 정도 되지 않았을까요? 그런데 게임 후반에는 오히려 소비량이 급격히 줄었던 것 같아요.”
소비자측으로부터의 주문은 꾸준히 4~8사이에 머물렀다는 것을 상기하면 당황스러운 결과였다.
왜 이러한 현상이 발생했을까?
대부분의 팀에서 [소매상]을 맡은 팀원들은 초반 자신의 재고가 12임을 감안하여 주문량을 4 또는 5정도만을 주문하였다. 따라서 상위업체들 (도매상,물류창고,공장) 역시 주문 및 생산을 적게하였다. 약 5~6일 후 소비자의 맥주구입이 늘어나기 시작하고 재고가 줄어들기 시작하자, [소매상]측은 급히 대량의 맥주를 주문하기 시작했다. 하지만 [공장]으로부터 [소매상]까지의 유통과정은 10일 이상 소요되기 때문에 재고가 떨어진 [소매상]의 마음을 더욱 다급하게 만들 뿐이었다. 이때부터 주문서에 기재된 주문량은 최소 20~50 단위로 급히 뛰기 시작했고 공장은 많은 양의 맥주를 생산해내기에 여념이 없었다. 게임이 후반으로 접어들자, 재고가 산더미같이 쌓인 [소매상]측에서는 주문을 아예 0으로 떨어뜨려버렸던 것이다. 결국 대부분의 팀에서 각 유통단계의 팀원들이 가진 재고는 100이상이었다.
왜 이러한 현상이 발생하는 것일까?
- 공장측에서는 소비자의 주문이 아닌 [물류센터]의 주문을 바탕으로 생산한다.
- 상당히 많은 [소매상]들이 매일 적은양의 주문을 하기보다는 2주에 한번 또는 한달에 한번 정도 대량주문을 하는 편이다.
- 모두들 주문에 즉각대응을 하기 위하여 예상되는 주문보다 많이 재고를 유지하고 싶어 한다.
결국 모든 유통단계의 관계자들이 소비자를 바라본 것이 아니라 자신의 고객(하위유통업자)의 주문서를 기반으로 일했던 것이 화근이었다. 이렇게 [소매상]의 불규칙한 주문서에 의하여 [공장]의 생산량이 급격하게 변하는 현상을 “채찍효과”라고 한다.
Seminar 3: Beer Game
-Analysis
Group: 1 (Morning Section) Course: Contemporary Business Processes Date: 2009-10-30
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Table of Contents
1. Introduction ...................................................................................................................... 3
1.1 Definition of the Bullwhip Effect in Supply Chains? ................................................ 3
1.2 Description of the “Beer Game” ................................................................................ 3
1.3 Description of group process...................................................................................... 3
2. SWOT Analysis of the “Beer Game”.................................................................................. 4
3. Group outcomes according to the “Beer game”................................................................5
4. Lessons learnt ....................................................................................................................... 5 Appendix ................................................................................................................................... 7 Bibliography ............................................................................................................................. 9
1. Introduction
1.1 Definition of the Bullwhip Effect in Supply Chains?
According to the article (1997) of Lee, Padmanabhan & Wang the Bullwhip Effect describes the occurrence of a steady consumer demand of one product, “the demand orders variabilities in the supply chain were amplified as they moved up the supply chain”. One reason for this variability is the self-orientation of companies in solving their problems. The Bullwhip Effect is occurring in many industries and includes consequences like for example high stock levels, lower customer service, poor capacity utilisation, aggravated problems with demand forecasting as thus high costs and low levels of inter-firm trust. (www.quickmba.com).
1.2 Description of the “Beer Game”
The so called “Beer Game” is used as an illustration for the “Bullwhip Effect”. It is a “laboratory replica”(Senge, 1990) of real supply chain process including a four stage supply chain (retailer, wholesaler, distributor and factory). The task hereby is to produce and deliver beer according to the customers demand. To emphasize the importance of time one structural aspect is delay which is due to logistics and production time. Necessary rules are that the participants are not allowed to communicate with each other and order decisions are made on former orders from the downstream site. The aim of the “Beer Game” is to visualize the challenges within the supply chain (Lee, Padmanabhan, Whang, 1997).
1.3 Description of group process
We were supposed to play the “Beer Game” for 70 days but due to time consuming confusions and miscalculations we finished the game on the 23 day. To sort out this disarrangement problem we decided to chose on person who was in charge of coordination each single step and day. However, it was hard to stick to the rules as some group members were confused and thus led to wrong calculations which infected the orders and thus the delivers of all parties. Nevertheless, after some start-up problems, the group was establishing a well-structured process. In addition there was a good group dynamic development which included the support by the observers.
2. SWOT Analysis of the “Beer Game”
Strengths:
The game gave us the change to face the bullwhip effect ourselves. A practical experience is lasting longer than just theoretical approaches.
Weaknesses:
During the game, the players were not allowed to communicate, which lead to unpredictability of the following stages. Every order was not foreseeable in its amount and mainly a short term reaction, without strategic or long term planning. Peak effects followed, resulting in either storage or shortage. Therefore, the customer service was neglected. Additionally, we were not aware of the cost caused by storage and shortage. In comparison, a stock is preferable to a shortage, but we were lacking in strategies.
Opportunities:
The biggest opportunities to change the outcomes can be find in a strategic planning and coordination, based on communication or trust. About day 20 we started a stabilization process to reduce shortages.
Threats:
On other hand, the bullwhip and panic effects are likely to increase as fast term reaction. The poor customer service might lead to lose customers in reality. An interruption of the whole supply chain was a possible outcome for the following days after day 23.
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3. Group outcomes according to the “Beer game”
It was difficult to predict the customers demand: one day it was 0, the next day it was
18. This circumstance caused appearance of excess stocks of beer or shortage. However, it was possible to influence the behavior of the following member of the supply chain by forming own orders. Nevertheless, to get response for an order took approximately 5 days to deliver the ordered amount. After noticing the tendency, the team tried to take it into consideration for further orders. The mistake, most done at the beginning was to overestimate the situation of customer’s demand, to analyze the situation by random case which mislead. To focus more on the general situation than on random cases in the supply chain is one main outcome. Furthermore, we realized the communication and coordination would have lead to more success.
4. Lessons learnt
? Communication/coordination
? Stock and stable orders
? Organization inventory
Communication is the key factor for interacting between companies. As the stages in the beer game are interlinked and interdependent, communication and coordination of orders and strategies can avoid the bullwhip effect partly and lead to less extreme fluctuation within the supply chain. One outcome might be holding stock and stable ordering processes. This means more frequent orders, based on long-term expectancies and strategies, instead of risky short-term reactions and fluctuations. Holding a small stock is advisable, as it is less costly than shortage. This safety stock is the minimum level of stock providing capacity in the period between reordering and delivery of orders, also called replenishment time. Replenishment is a term, referring to organization inventory.
Figure
To sum up, as the supply chain is a chain, every element is interlinked and connected with each other in a direct or indirect way. To gain efficiency and appropriated supply, communication and coordination are the key figures for good customer service and low costs.
Procurement (help.sap.com)
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Course: Contemporary Business Process Assignment: Week 3
Article 1: The Bullwhip Effect in Supply Chains (by Lee H.L, Padmanabhan, V., Whang, S.) Q1: How can a company counter the Bullwhip Effect in Supply Chains?
The Bullwhip Effect in Supply Chains can be avoided by four strategies:
According to Lee and others “Bullwhip effects are created when supply chain members process the demand input from their immediate downstream member in producing their own forecasts. By allocate a transparent demand data of the downstream members available to the upstream site. Consequently all supply chain members can rely on the same raw data. Another approach is to bypass the supply chain by direct selling.
Another reason for the bullwhip effect is order batches which are caused through high cost of transportation. Suggested solutions in this case are mixed-SKU orders, the use of third party logistic companies as well as regular delivery appointments with customers.
Price stabilization is also a method of avoiding the bullwhip effect. In this connection the level of wholesale price discounting is reduced by establishing a uniform wholesale pricing policy.
Last but not least a company should eliminate gaming in shortage situations by sharing capacity and inventory information to avoid customers’ fears. At the same time companies can implement a stricter cancellation policy. 1
1 Lee, H.L., Padmanabhan, V., Whang, S.The Bullwhip Effect in Supply Chains.Sloan Management Review (1997)
Group 2 -1 -01.11.2009-11-01