Beer Game developed by Slaon School of Management didn¡¦t add price variable into the game. It¡¦s reasons were : (1) As long as there is time delay, it will induce dynamic complexity. (2) If there is price variable, maybe we can¡¦t observe patterns and structure. In the research, we try to add price variable into Beer Game to verify the statement made by Slaon School of Management. Besides, we can explore whether it will influence players¡¦ decisions or not. The learning effects are also we concern about. After a few experiment, althought bullwhip effect is still existing, it¡¦s not much apparent then before. Besides, players are affected by price variables. From discussions after the game, we can find players lack systems thinking, they have misperceptions of feedback and get used to put blame on others. Those learning effects are the same as traditional beer game induced. However, beer game with price variable can conclude many behaviors made by players. To contrast with the panic buying and stock conditions, such as respirators panic buying in 2003, toilet paper price rise caused by pulp cost increased in 2004, players can simulate the real world throuth playing the game. They can reflect and learn, then bring this experience into real life.

This paper constructs a model of a supply chain to examine how demand volatility is passed upstream through the chain. In particular, we seek to determine how likely it is that the chain experiences a bullwhip effect, where the variance of the upstream firm’s production exceeds the variance of the downstream firm’s sales. We show that the bullwhip effect is more likely to occur and is greater in size in supply chains in which inventory control is centralized rather than decentralized, that is, exercised by the downstream firm.

Effective supply chain management gains much attention from industry and academia because it helps firms across a supply chain to reduce cost and improve customer service level efficiently. Focusing on one of the key challenges of the supply chains, namely, demand uncertainty, this dissertation extends the work of Zhao, Xie, and Leung so as to examine the effects of forecasting method selection coupled with information sharing on supply chain performance in a dynamic business environment. The results of this study showed that under various scenarios, advanced forecasting methods such as neural network and GARCH models play a more significant role when capacity tightness increases and is more important to the retailers than to the supplier under certain circumstances in terms of supply chain costs. Thus, advanced forecasting models should be promoted in supply chain management. However, this study also demonstrated that forecasting methods not capable of modeling features of certain demand patterns significantly impact a supply chain's performance. That is, a forecasting method misspecified for characteristics of the demand pattern usually results in higher supply chain costs. Thus, in practice, supply chain managers should be cognizant of the cost impact of selecting commonly used traditional forecasting methods, such as moving average and exponential smoothing, in conjunction with various operational and environmental factors, to keep supply chain cost under control. This study demonstrated that when capacity tightness is high for the supplier, information sharing plays a more important role in effective supply chain management. In addition, this study also showed that retailers benefit directly from information sharing when advanced forecasting methods are employed under certain conditions.

Over the past of decade, the bullwhip effect has increasingly become a popular topic for researchers and practitioners in the area of supply chain management since it negatively influences cost, inventory, reliability and other important business processes in supply chain agents. Although there are many remedies for the bullwhip effect summarised in existing literature, it still occurs in several industries. This is partly because it is difficult to apply the results from existing research which analyse the bullwhip effect mainly in a simple supply chain. In addition, several tools and methodologies developed are used for analysing the bullwhip effect in a simple supply chain with several constraints. Therefore, this research aims to develop a unique simulation approach based on system dynamics modelling and Adaptive Network Based Fuzzy Inference System (ANFIS) for quantifying and reducing the bullwhip effect in a multi-product, multi-stage supply chain. System dynamics modelling which is a powerful simulation approach for studying and managing complex feedback system was selected as a main tool in this research. In addition, ANFIS was implemented in system dynamics modelling in order to increase the reliability of a system dynamics model for modelling soft variables. The proposed model covers variables influencing the bullwhip effect which are the structure of supply chain network, supply chain contributions and supply chain performances. As a result, a two layer simulation with three generic models was developed. The flexibility of this proposed model is the ability to model various types of ordering policies which are basic inventory policies, Material requirement planning (MRP) system and Just in time (JIT) approach. Three actual manufacturing supply chains were used as case studies to validate and demonstrate the flexibility of the model developed in this research. This model satisfactorily quantifies the bullwhip effect and the bullwhip effect levels identified in these case studies are significantly decreased by using the proposed simulation model. The successful results indicate that the model can be a useful alternative tool for supply chain managers to quantify and reduce the bullwhip effect in multi-product, multi-stage supply chains.

Over the past of decade, the bullwhip effect has increasingly become a popular topic for researchers and practitioners in the area of supply chain management since it negatively influences cost, inventory, reliability and other important business processes in supply chain agents. Although there are many remedies for the bullwhip effect summarised in existing literature, it still occurs in several industries. This is partly because it is difficult to apply the results from existing research which analyse the bullwhip effect mainly in a simple supply chain. In addition, several tools and methodologies developed are used for analysing the bullwhip effect in a simple supply chain with several constraints. Therefore, this research aims to develop a unique simulation approach based on system dynamics modelling and Adaptive Network Based Fuzzy Inference System (ANFIS) for quantifying and reducing the bullwhip effect in a multi-product, multi-stage supply chain. System dynamics modelling which is a powerful simulation approach for studying and managing complex feedback system was selected as a main tool in this research. In addition, ANFIS was implemented in system dynamics modelling in order to increase the reliability of a system dynamics model for modelling soft variables. The proposed model covers variables influencing the bullwhip effect which are the structure of supply chain network, supply chain contributions and supply chain performances. As a result, a two layer simulation with three generic models was developed. The flexibility of this proposed model is the ability to model various types of ordering policies which are basic inventory policies, Material requirement planning (MRP) system and Just in time (JIT) approach. Three actual manufacturing supply chains were used as case studies to validate and demonstrate the flexibility of the model developed in this research. This model satisfactorily quantifies the bullwhip effect and the bullwhip effect levels identified in these case studies are significantly decreased by using the proposed simulation model. The successful results indicate that the model can be a useful alternative tool for supply chain managers to quantify and reduce the bullwhip effect in multi-product, multi-stage supply chains.

O funcionamento da cadeia de suprimentos é um tema atual que tem motivado muitas pesquisas para o entendimento da sua dinâmica como fonte de obtenção de vantagem competitiva. O bullwhip effect - efeito de oscilação de demanda dentro da cadeia de suprimentos - é um dos causadores de ineficiências operacionais e de consequentes gastos desnecessários. Esse fenômeno ainda não foi estudado em sua totalidade; a maioria das pesquisas até então utilizaram-se de análises quantitativas, não levando em conta fatores qualitativos presentes em situações de oscilação de demanda, tais como: a experiência do programador de demanda, as capabilidades desenvolvidas pela empresa e os métodos que ela utiliza para integrar o conhecimento sobre o fenômeno. Esta pesquisa contribui nesse sentido. Coloca em evidência, por meio da análise qualitativa do bullwhip effect e dos fundamentos do processo de capacidade absortiva. Busca-se integrar esses dois conceitos, até então não abordados conjuntamente. A reunião desse referencial e dos resultados obtidos por intermédio das observações deverá fornecer subsídios para a melhor compreensão do fenômeno. A estratégia de pesquisa selecionada se deu por meio de estudos de caso com três empresas brasileiras, de diferentes setores. Entrevistaram-se sete executivos das empresas, responsáveis pela programação da produção e a análise de demanda. Foram encontrados muitos pontos convergentes entre a literatura e a prática empresarial, principalmente sobre os fundamentos da capacidade absortiva em uma situação de bullwhip effect, como também entre as diferentes dimensões da capacidade absortiva per se. A principal contribuição da pesquisa está em integrar orientações teóricas e ações práticas desenvolvidas pelas empresas sob o bullwhip effect, relacionadas com a capacidade absortiva, dando destaque aos fatores humanos, o que propicia um referencial mais abrangente para examinar esses processos. Em nível gerencial, oferece-se subsídios aos gestores no aprimoramento de técnicas de absorção do conhecimento em situações de oscilação de demanda, tornando suas previsões e a produção mais eficientes. / The operation of the supply chain is a current topic and it has motivated many researches in order to understand its dynamic as source of obtaining competitive advantage. The bullwhip effect - the effect of oscillating demand inside the supply chain - is one of the originators of operational inefficiencies and consequent unnecessary expenditure. This phenomenon has not been studied in its totality yet; most researches have used quantitative analysis so far, not taking into account qualitative factors which are present in oscillating demand situations, such as: the experience of the demand manager, the capabilities developed by the company and the methods which it uses to integrate the knowledge about the phenomenon. This research contributes in this sense. It highlights through the bullwhip effect qualitative analysis and the process fundamentals of absorptive capacity. It pursuits to integrate these two concepts which have not thus far been approached together. The reunion of this reference and the obtained results through remarks should provide subsidies for better comprehension of the phenomenon. The research strategy selected was through case studies with three Brazilian companies of different sectors. Seven executives of the companies were interviewed; they are responsible for the production programming and for the demand analysis. Many convergent points were found between literature and the business practice, mainly concerning the fundamentals of absorptive capacity in a bullwhip effect situation, as well as among the different dimensions of absorptive capacity per se. The main contribution of the research is to integrate theoretical orientations and practical actions developed by the companies under the bullwhip effect, which are related to the absorptive capacity, highlighting to the human factors, which provides a reference more comprehensive to examine these processes. In a managerial level, subsidies are offered to the managers in the improvement of the absorption techniques of the knowledge in oscillating demand situations, making their forecasts and the production more efficient.

O funcionamento da cadeia de suprimentos é um tema atual que tem motivado muitas pesquisas para o entendimento da sua dinâmica como fonte de obtenção de vantagem competitiva. O bullwhip effect - efeito de oscilação de demanda dentro da cadeia de suprimentos - é um dos causadores de ineficiências operacionais e de consequentes gastos desnecessários. Esse fenômeno ainda não foi estudado em sua totalidade; a maioria das pesquisas até então utilizaram-se de análises quantitativas, não levando em conta fatores qualitativos presentes em situações de oscilação de demanda, tais como: a experiência do programador de demanda, as capabilidades desenvolvidas pela empresa e os métodos que ela utiliza para integrar o conhecimento sobre o fenômeno. Esta pesquisa contribui nesse sentido. Coloca em evidência, por meio da análise qualitativa do bullwhip effect e dos fundamentos do processo de capacidade absortiva. Busca-se integrar esses dois conceitos, até então não abordados conjuntamente. A reunião desse referencial e dos resultados obtidos por intermédio das observações deverá fornecer subsídios para a melhor compreensão do fenômeno. A estratégia de pesquisa selecionada se deu por meio de estudos de caso com três empresas brasileiras, de diferentes setores. Entrevistaram-se sete executivos das empresas, responsáveis pela programação da produção e a análise de demanda. Foram encontrados muitos pontos convergentes entre a literatura e a prática empresarial, principalmente sobre os fundamentos da capacidade absortiva em uma situação de bullwhip effect, como também entre as diferentes dimensões da capacidade absortiva per se. A principal contribuição da pesquisa está em integrar orientações teóricas e ações práticas desenvolvidas pelas empresas sob o bullwhip effect, relacionadas com a capacidade absortiva, dando destaque aos fatores humanos, o que propicia um referencial mais abrangente para examinar esses processos. Em nível gerencial, oferece-se subsídios aos gestores no aprimoramento de técnicas de absorção do conhecimento em situações de oscilação de demanda, tornando suas previsões e a produção mais eficientes. / The operation of the supply chain is a current topic and it has motivated many researches in order to understand its dynamic as source of obtaining competitive advantage. The bullwhip effect - the effect of oscillating demand inside the supply chain - is one of the originators of operational inefficiencies and consequent unnecessary expenditure. This phenomenon has not been studied in its totality yet; most researches have used quantitative analysis so far, not taking into account qualitative factors which are present in oscillating demand situations, such as: the experience of the demand manager, the capabilities developed by the company and the methods which it uses to integrate the knowledge about the phenomenon. This research contributes in this sense. It highlights through the bullwhip effect qualitative analysis and the process fundamentals of absorptive capacity. It pursuits to integrate these two concepts which have not thus far been approached together. The reunion of this reference and the obtained results through remarks should provide subsidies for better comprehension of the phenomenon. The research strategy selected was through case studies with three Brazilian companies of different sectors. Seven executives of the companies were interviewed; they are responsible for the production programming and for the demand analysis. Many convergent points were found between literature and the business practice, mainly concerning the fundamentals of absorptive capacity in a bullwhip effect situation, as well as among the different dimensions of absorptive capacity per se. The main contribution of the research is to integrate theoretical orientations and practical actions developed by the companies under the bullwhip effect, which are related to the absorptive capacity, highlighting to the human factors, which provides a reference more comprehensive to examine these processes. In a managerial level, subsidies are offered to the managers in the improvement of the absorption techniques of the knowledge in oscillating demand situations, making their forecasts and the production more efficient.

O funcionamento da cadeia de suprimentos é um tema atual que tem motivado muitas pesquisas para o entendimento da sua dinâmica como fonte de obtenção de vantagem competitiva. O bullwhip effect - efeito de oscilação de demanda dentro da cadeia de suprimentos - é um dos causadores de ineficiências operacionais e de consequentes gastos desnecessários. Esse fenômeno ainda não foi estudado em sua totalidade; a maioria das pesquisas até então utilizaram-se de análises quantitativas, não levando em conta fatores qualitativos presentes em situações de oscilação de demanda, tais como: a experiência do programador de demanda, as capabilidades desenvolvidas pela empresa e os métodos que ela utiliza para integrar o conhecimento sobre o fenômeno. Esta pesquisa contribui nesse sentido. Coloca em evidência, por meio da análise qualitativa do bullwhip effect e dos fundamentos do processo de capacidade absortiva. Busca-se integrar esses dois conceitos, até então não abordados conjuntamente. A reunião desse referencial e dos resultados obtidos por intermédio das observações deverá fornecer subsídios para a melhor compreensão do fenômeno. A estratégia de pesquisa selecionada se deu por meio de estudos de caso com três empresas brasileiras, de diferentes setores. Entrevistaram-se sete executivos das empresas, responsáveis pela programação da produção e a análise de demanda. Foram encontrados muitos pontos convergentes entre a literatura e a prática empresarial, principalmente sobre os fundamentos da capacidade absortiva em uma situação de bullwhip effect, como também entre as diferentes dimensões da capacidade absortiva per se. A principal contribuição da pesquisa está em integrar orientações teóricas e ações práticas desenvolvidas pelas empresas sob o bullwhip effect, relacionadas com a capacidade absortiva, dando destaque aos fatores humanos, o que propicia um referencial mais abrangente para examinar esses processos. Em nível gerencial, oferece-se subsídios aos gestores no aprimoramento de técnicas de absorção do conhecimento em situações de oscilação de demanda, tornando suas previsões e a produção mais eficientes. / The operation of the supply chain is a current topic and it has motivated many researches in order to understand its dynamic as source of obtaining competitive advantage. The bullwhip effect - the effect of oscillating demand inside the supply chain - is one of the originators of operational inefficiencies and consequent unnecessary expenditure. This phenomenon has not been studied in its totality yet; most researches have used quantitative analysis so far, not taking into account qualitative factors which are present in oscillating demand situations, such as: the experience of the demand manager, the capabilities developed by the company and the methods which it uses to integrate the knowledge about the phenomenon. This research contributes in this sense. It highlights through the bullwhip effect qualitative analysis and the process fundamentals of absorptive capacity. It pursuits to integrate these two concepts which have not thus far been approached together. The reunion of this reference and the obtained results through remarks should provide subsidies for better comprehension of the phenomenon. The research strategy selected was through case studies with three Brazilian companies of different sectors. Seven executives of the companies were interviewed; they are responsible for the production programming and for the demand analysis. Many convergent points were found between literature and the business practice, mainly concerning the fundamentals of absorptive capacity in a bullwhip effect situation, as well as among the different dimensions of absorptive capacity per se. The main contribution of the research is to integrate theoretical orientations and practical actions developed by the companies under the bullwhip effect, which are related to the absorptive capacity, highlighting to the human factors, which provides a reference more comprehensive to examine these processes. In a managerial level, subsidies are offered to the managers in the improvement of the absorption techniques of the knowledge in oscillating demand situations, making their forecasts and the production more efficient.

In this study, I have developed the theoretical concept Service Bullwhip Effect (SBWE) by examining it within the professional services context through a single case study at a Swedish consultancy firm. The research questions that have been guiding the study are the following: F1. How does the service bullwhip effect differ in professional service firms compared with other service firms? F2. How can the service bullwhip effect be mitigated within professional service firms? The purpose of the study is thus to contribute to the research area of Service Supply Chain Management, and its theoretical concept SBWE. I do this by studying the SBWE within the context of professional service firms (PSF), and analyze how it differentiate itself from other service firms, and how it can be mitigated within this context. The methodology used have been a combination of data sources that were collected in the form of primary qualitative data, and secondary quantitative data from the service supply chain of a consultancy firm. My findings indicate that a SBWE exists to some extent within the professional services context. Its presence, however, was limited due to the inherent characteristics of PSFs. From this I put forward the following three propositions: H1. The service bullwhip effect exists to some extent within professional service firms, and primarily in the form of a negative effect due to a work underdelegation. H2. Shortage gaming does not exist within the professional services context due to the close relation these firms have with its customers. H3. Batch ordering exists within professional service firms in the form of project clusters. Furthermore, managerial recommendations are also provided on how to mitigate the SBWE within the PSFs. My findings points towards a reduced emphasis on the individual utilization rate for the more senior consultants within the firm. Instead, I see that a larger emphasis should be put on the economic performance of projects when evaluating consultants that are project leaders. Research implications & limitations - As a single case, the research achieves a significant depth within the studied consultancy context, but have a limited generalizability. Therefore, the developed propositions will need to be tested within other types of PSFs, and thus with different sets of characteristics. / I denna studie har jag byggt vidare på teorier kopplade till Service Bullwhip Effect (SBWE) genom att undersöka konceptet inom den kunskapsintensiva tjänstesektorn. Detta har jag gjort genom en fallstudie på analys- och teknikkonsultföretaget WSP i form av en kvalitativ och kvantitativ datainsamling. Den insamlade empirin jämfördes med resultat från tidigare studier för att analysera huruvida SBWE existerar inom kunskapsintensiva tjänsteverksamheter, och hur denna effekt i så fall skiljer sig från andra tjänsteverksamheter. Utifrån analysen har jag fört en diskussion med koppling till de forskningsfrågor som styrt studien: F1. Hur skiljer sig Service Bullwhip Effect inom kunskapsintensiv tjänsteverksamhet jämfört med andra tjänsteverksamheter? F2. Hur kan Service Bullwhip Effect hanteras inom en kunskapsintensiv tjänsteverksamhet? Studiens slutsatser utifrån den första forskningsfrågan (F1) pekar bland annat på att en SBWE existerar till viss del inom kunskapsintensiva tjänsteföretag. Dock inte i samma utsträckning som inom icke kunskapsintensiva tjänsteverksamheter. Dessa slutsatser summeras i form av tre nya hypoteser: H1. The Service Bullwhip Effect existerar till viss del inom kunskapsintensiv tjänsteverksamhet, och främst i form av en negativ effekt på grund av en underdelegation av arbetsuppgifter. H2. Shortage Gaming existerar inte inom kunskapsintensiv tjänsteverksamhet på grund av den nära relationen med kunderna. H3. Batch ordering existerar inom kunskapsintensiv tjänsteverksamhet i form av uppdragskluster. De dragna slutsatserna konfirmerar därmed teorierna inom området samtidigt som branschspecifika adapteringar av teorin föreslås utifrån de särskilda förhållandena som råder inom den kunskapsintensiva tjänstesektorn. Dessa slutsatser har dock en låg generaliserbarhet och validitet då jag i denna studie undersökt ett specifikt fall, och därmed presenterar jag mina slutsatser i form av hypoteser som kräver testning genom ytterligare studier. Slutligen ger jag ledningsmässiga rekommendationer utifrån den andra forskningsfrågan (F2). Dessa rekommendationer har sitt fokus på hur SBWE kan motverkas utifrån det specifika fallet inom konsultföretaget, och hur en rådande underdelegation kan bearbetas av verksamhetens ledning. För att motverka SBWE, och en underdelegation av arbetsuppgifter, så rekommenderar jag bland annat att seniorkonsulterna utvärderas med en låg prioritet utifrån deras beläggningsgradskrav, och med hög prioritet utifrån deras ansvar över uppdragsekonomin.

The bullwhip effect is defined as an upstream amplification of demand variability and has received interest within multinational companies for decades. As early as in the 1950’s, Forrester (1958) discussed what is today known as the bullwhip effect, which has a negative impact on the customer service, costs, and inventory investment in a supply chain (Lee et al., 1997). Even though the bullwhip effect has been noticed in various industries, the consequences, in form of decreased availability and increased costs the further up the supply chain the bullwhip goes, still remain. The employees at Volvo Group Service Market Logistics suspect that their supply chain has been affected by the bullwhip effect and want to know if it is correct and subsequently know why it has occurred. Therefore, this master’s thesis highlights the root causes of the bullwhip effect and presents strategies to mitigate it. To understand how the bullwhip effect affected the Volvo Group Service Market Logistics’ supply chain, the purpose was formulated as follow: The purpose of this study is to identify events in the Volvo Group Service Market Logistics’ supply chain where the bullwhip effect has occurred, its root causes, and how to reduce or eliminate the bullwhip effects.  The studied flow was from the Central Distribution Center (CDC) in Ghent, to the Regional Distribution Center (RDC) in Brazil, to the Dealers associated to the RDC in Brazil, and the customers. Data was collected from each node and events were studied to find bullwhip events. After sorting out the part numbers that passed the criteria for bullwhip events, the amount of data had to be reduced even more. A couple of different conditions were applied which resulted in four suitable bullwhip events. Thereafter, the authors conducted interviews with Logistics Managers at each node of the supply chain to find the root causes of the bullwhip effect in each studied event.  Among the several found root causes, lack of information transparency was the most frequent occurring root cause, found in three out of four studied bullwhip events. Insufficient communication and lack of information sharing cause bullwhip effects, and the authors found that improved communication both between and within the nodes will contribute to better planning, and consequently avoided bullwhip effects. Other root causes found were issues with the ordering system, lack of learning and experience, neglected lead times, fear of empty stock, price fluctuations, and phase-out of the spare part.  To reduce or eliminate the bullwhip effect, the focus was on mitigating the root causes since the root causes create opportunities for the bullwhip effect to occur. Four suggestions were given with suitable mitigation strategies found in the literature, where the four suggestions were sales campaigns, prepare for boosts, keep track of manually placed orders, and ordering system and Logistics Manager behavioural issues. The suggestions could then be connected to the different found root causes. The stated suggestions and mitigation strategies focused on mitigating the root causes in a long-term perspective and consequently the bullwhip effect itself.