Bull Whip Research Articles

Peer Teaching: A Pedagogic Method for Higher Education

Teaching the concepts of numerical courses is a significant challenge for engineering and the management students with innovative teaching pedagogy. Engineering and management education requires pedagogies that provide conceptual framework and that develop analytical and decision making skills to prepare students to face the complex problems. Class room dynamics add values to learning among students. Activities chosen by the professor can be central to many progressive learning experiences. Therefore, we experimented peer teaching methodology for post graduate management students (MBA) for teaching supply chain management concepts and application through a simulation game called “Beer game”. The Beer Game players’ experiences typical supply chain coordination problems, wherever information sharing and collaboration is missing. As a part of the peer group learning initiative, the senior batch students were encouraged to play the game with their juniors. Game demonstrates that communication gap and lack of collaboration can leads to an effect called “the bull whip effect” in the supply chain due to varying inventory levels at each link in the supply chain. Additionally, it was also intended for the students to develop their critical thinking, complex problem solving, leadership, negotiation, collaboration and communication skills in the process. Study results demonstrated a statistical significance in learning outcome, participant satisfaction. Learners results have shown a greater and high learning levels for the peer teachers. This peer teaching approach can be recommended to incorporated in teaching pedagogy for engineering and management students as one of the active learning method.

An Analysis on the Bullwhip Effect of Stationery Supply Chain Network in Korea

본 논문은 문구산업의 공급사슬네트워크에서 채찍효과의 원인을 실증적으로 규명하고 이를 감소시킬 수 있는 대안을 제안한 다. 기존 물류관련 문헌이 자본재 산업 중 특히 성장기 제품의 채찍효과를 수요기반 측면으로 분석하고 있는 반면, 본 논문은 보다 일반적인 소비재 산업 내 성숙기 제품의 공급사슬에서 발생하는 채찍효과의 구조적 원인을 밝히는 것을 목적으로 한다. 이를 위해 본 연구는 먼저 국내 문구산업의 공급사슬 내 기업들로부터 수집한 실제 매출 자료를 이용하여 공급사슬네트워크에서의 채찍효과를 확인하고 기존 문헌으로부터 도출한 분석틀을 적용하여 채찍효과의 4가지 원인과 대응 방안을 분석한다. 특히 본 논문은 실증적 연구방법으로써 공급사슬네트워크 내 기업의 실무 담당자들과의 심층면접을 통해 수집한 자료를 활용하여 계층적 분석 과정(AHP) 모형을 구축하고 분석함으로써, 실무자들이 고려하는 공급사슬네트워크에서 채찍효과의 중요 원인을 실증적으로 밝힌 다. 이에 따른 본 연구의 결과 소비재 산업 중 특히 성숙기 제품의 특성을 지닌 문구산업의 공급사슬네트워크에서 채찍효과의 존재를 확인할 수 있었으며, 이의 주요 원인이 기업의 정책적인 부분에 해당하는 가격변동으로 확인되었다. 이는 기존 문헌의 수요 예측의 수정이라는 연구 결과와는 대비되는 것으로 공급기반 측면에서 채찍효과를 감소시킬 수 있는 방안을 고려할 필요가 있음을 보여준다. 본 연구의 결과는 소비재 산업 특히 성숙기 제품의 공급사슬네트워크에서 공급업체의 가격 전략에 대한 새로운 가능 성을 제시하는 한편, 물류 네트워크에서 유통업체와 같이 최종 소비자와 접점을 이루는 조직이 구매 또는 판매 경로를 선택하기 위한 효과적인 방법으로 확장될 수 있다.The purpose of this study is to empirically identify the bullwhip effect on the stationery supply chain network and to propose an alternative solution to reduce it. Existing literature related to logistics analyzes the bullwhip effect of the capital goods industry, especially the products during the growth period, at the aspect of the demand base. This article, however, is focusing on structural cause of the bullwhip effect in the supply chain of more general consumer goods during the mature period. To this end, the bull whip effect in the supply chain network was confirmed using the actual sales data collected from the companies in the supply chain of the domestic stationery industry. Then the four causes and countermeasures of bullwhip effect were analyzed by applying the analysis framework derived from existing literature. In particular, this article used an empirical research method. By constructing and analyzing AHP (Analytic Hierarchy Process) model using the materials collected through in-depth interviews with working level respondents of the companies in the supply chain network, significant causes of bullwhip effect in the supply chain network were identified. As a result, it was confirmed that there was bullwhip effect in the stationery supply chain network which could be characterized as mature period goods among consumer goods. It was also confirmed that the major cause was price fluctuation falling under the division of corporate policy. The result of this study is not consistent with previous studies which addressed the demand signal processing. It showed the needs to consider the method to reduce bullwhip effect from the supply base. The results of this study suggest new possibilities for the suppliers pricing strategy for the consumer goods in the mature period in the supply chain network. It can be extended to an effective way to select a sales or marketing channel for organizations that are in contact with end consumers in the logistics network.

Analyzing drivers of risks in electronic supply chains: a grey–DEMATEL approach

Supply chains today are exposed to a lot of turbulence with outsized unforeseen penalties of seemingly contained events. It is significant for practitioners to identify and classify risks into various categories for the ease of monitoring. After the risks are classified, drivers for the particular risk need to be identified and addressed. A distinctive risk driver can be the instigating cause for many auxiliary drivers of risks; alternatively, a risk driver can be a secondary driver initiated as the effect of one or more primary drivers. This study contributes to ascertain and construct a causal effect diagram on predominant risk drivers archetypally seen in electronic supply chains. A combination of grey theory and DEMATEL methodologies has been employed in this study and a case evaluation was also done. The combined methodology is to deal with judgmental decisions and to transmute them to interpretable cause–effect diagraphs. It is evident from the results of proposed model that the risk drivers are interconnected and one risk driver can be the cause/effect of one or more risk drivers. Fluctuating exchange rates is found to be the principal causal driver initiating the effects of other risk drivers too, trailed by loss of information system and supply failure. Risk arising from the cost of capacity is the effect driver for most of the risk drivers, followed by bull whip effects and capacity inflexibility. In conclusion, the benefits of the research are of twofold, first to recognize and categorize the drivers of major supply chain risks and the other is to effectively identify the chief risk drivers, where the managers and practitioners could really concentrate on. A significant managerial implication of this research is that steps taken for curtailing the causal risk drivers can sequentially lead to dwindled effect risk drivers, leading to enhanced management of supply chain vulnerability.

Process Control, the Bull Whip Effect and the Supply Chain

The purpose is to introduce the demand for statistical quality control practice in the supply chain environment. We show both the need and application of these measures, especially the need for multivariate quality concepts to reduce the costs of operating supply chains, to control the flow throughout the supply chain and in the dynamic behavior of supply chains to utilize concepts associated with multivariate methods and auto correlated variables. We note that the quality output is as important as the “bull whip” efficiency in the supply chain.

基于博弈分析的供应链牛鞭效应削减对策

基于博弈分析的供应链牛鞭效应削减对策

Modelling, simulation and analysis of control mechanism of a dynamic supply chain system considering supply-price trade-off, using control theory

Purpose – The objective of this work is to develop a model that can be used for simulation of different parameters including price, subjected to different control strategies. Design/methodology/approach – The entire supply chain can be modelled by combining the transfer function into a closed loop system. The transfer function of each entity in the supply chain can be obtained by using the control theory tools. The model can be approximated as a linear discrete system with various operating constants, like lead time, price, order policy and supply. Findings – The continuous replenishment ordering policy for a distribution node in a supply chain was analyzed using the z-transform. Characteristic equations of the closed loop transfer function are obtained. The bullwhip (BW) effect is analyzed. Study proves that the BW effect is in evitable if the standard heuristic ordering policy is employed with demand forecasting; also the paper analysed price supply trade-off for dynamic demand and supply. Simulation results show that BW is less in PI and simple p-only with cascade control. Robust control and PD, PID control results are not shown in this literature, and it is subject to further research. Originality/value – Research is original, it can be applicable in today's dynamic world, due to globalization, it is necessary to have a automated machine that can handle most of supply chain decision.

Sounds Scary? Lack of Habituation following the Presentation of Novel Sounds

BackgroundAnimals typically show less habituation to biologically meaningful sounds than to novel signals. We might therefore expect that acoustic deterrents should be based on natural sounds.MethodologyWe investigated responses by western grey kangaroos (Macropus fulignosus) towards playback of natural sounds (alarm foot stomps and Australian raven (Corvus coronoides) calls) and artificial sounds (faux snake hiss and bull whip crack). We then increased rate of presentation to examine whether animals would habituate. Finally, we varied frequency of playback to investigate optimal rates of delivery.Principal FindingsNine behaviors clustered into five Principal Components. PC factors 1 and 2 (animals alert or looking, or hopping and moving out of area) accounted for 36% of variance. PC factor 3 (eating cessation, taking flight, movement out of area) accounted for 13% of variance. Factors 4 and 5 (relaxing, grooming and walking; 12 and 11% of variation, respectively) discontinued upon playback. The whip crack was most evocative; eating was reduced from 75% of time spent prior to playback to 6% following playback (post alarm stomp: 32%, raven call: 49%, hiss: 75%). Additionally, 24% of individuals took flight and moved out of area (50 m radius) in response to the whip crack (foot stomp: 0%, raven call: 8% and 4%, hiss: 6%). Increasing rate of presentation (12x/min ×2 min) caused 71% of animals to move out of the area.Conclusions/SignificanceThe bull whip crack, an artificial sound, was as effective as the alarm stomp at eliciting aversive behaviors. Kangaroos did not fully habituate despite hearing the signal up to 20x/min. Highest rates of playback did not elicit the greatest responses, suggesting that ‘more is not always better’. Ultimately, by utilizing both artificial and biological sounds, predictability may be masked or offset, so that habituation is delayed and more effective deterrents may be produced.

MasDISPO_xt: Annealing Furnace Planning inside the Supply Chain of Steel Production

The production of steel normally constitutes the inception of many Supply Chains in different areas of industry. Therefore, steel manufacturing companies are strongly affected by bull whip effects and other unpredictable influences along their production chains. In the course of these integrated operations, making the right decision at a certain stage can be the difference between earning or losing a great benefit. Improving their operational efficiency is required to keep a competitive position on the market. Therefore, flexible planning and scheduling systems are needed to support these processes, which are based on considerable amounts of data, hardly processable manually anymore. MasDISPO_xt is an agent-based generic online planning and scheduling system for the observation on MES-level of the complete Supply Chain of Saarstahl AG, a globally respected steel manufacturer. This paper concentrates on the planning of the annealing furnaces as a representative example of the rough and detailed planning required in such an environment. The allocation of available capacities of annealing furnaces including alternatives to accepted orders is based on Simulated Trading to produce an evenly distributed rough planning regarding flexibility. As representative for the detailed planning, the solution for the batch-type annealing furnace is explained in detail.

Optimizing order fulfillment using design for six sigma and fuzzy logic

Supply chain management aims to add value across the supply chain and customer service is now a major strategic issue. Supply chains are complex and subject to variables of forecast, supply, process, and transportation which can lead to problems such as the bull whip effect, product lateness, damaged goods and stock outs. A key issue facing companies today is how to monitor and control performance across the chain. This paper presents Design for Six Sigma (DFSS), which focuses on customer requirements from the onset, as an effective methodology for monitoring and controlling supply chain variables, optimizing supply chain processes and meeting customer’s requirements. By applying DFSS methodology to the key supply chain process of order fulfillment, a customized representation of detailed activities of order fulfillment processes is demonstrated providing key performance indicators. A theoretical transfer function for predicting the performance of the perfect order incorporating fuzzy set theory provides a way of monitoring supply chain performance.

Supply Chain Dynamics, a Case Study on the Structural Causes of the Bullwhip Effect

This is a case study about the mod el ling of a sup ply chain de ci sion struc ture of a Mex i can bot tling com pany. We find that by mod el ling the in for ma tion and de ci sion struc ture of sup ply chains, it is pos si ble to iden tify man a ge rial pol i cies and in for ma tion flows that dis tort and am plify mar ket de mand sig nals. In the sec ond part of the pa per we use two sce nar ios to ana lyse var i ous changes in pol i cies. This pa per il lus trate not only an in no va tive form to study the Bull whip Ef fect nor only a dif fer ent way to model sup ply chains us ing Sys tem Dy nam ics, but also it es tab lishes a re la tion ship be tween in for ma tion struc tures, de ci sions rules, and de mand dis tor tion in sup ply chains.

David Walker's Appeal in Four Articles; Together with a Preamble to the Coloured Citizens of the World (review)

188CIVIL WAR HISTORY has produced a sound study of the characteristics and behavior of the group as a whole. In all instances his findings add depth, substance, or corrective to the generalizations of earlier students of slavery. Professor Scarborough's findings are, in brief, that the great majority of the plantation overseers were native southerners of the yeoman farmer class; that they were men of average competence, humaneness, and conscientiousness; and that they exercised a vital function in the running of the plantations. The author sharpens the effect of his conclusions by presenting them as a countertheme to the Simon Legree tradition about overseers. Unquestionably the overseer has shared with the slave trader the villains role in the abolitionist script of the slavery tragedy; and even as sympathetic a student of the institution as Professor U. B. Phillips described the overseers as being "crude in manner, barely literate, commonplace in capacity, capable only of ruling slaves by severity." Professor Scarborough convincingly challenges this sweeping characterization. Yet, the present book is not so much a ground breaker as it is a cultivator and fertilizer in its reappraisal of the overseer's nature; for many recent students of slavery have reached comparable, if tentative, conclusions. The Overseer is not a sparkling work at any point; and here and there the literary style falls into a pedantic exposition on sources of information and methods of analysis and presentation. But the book is the product of thorough research, and it closes a serious gap in the literature on the Old South. It will probably long remain the definitive monograph on the subject. „, , ...Charles P. Roland lulane University David Walker's Appeal in Four Articles; Together with a Preamble to the Coloured Citizens of the World. Edited by Charles M. Wiltse. (New York: Hill and Wang, 1965. Pp. xii, 78. $1.25.) The timeliness of this work, which first appeared in 1829, is attested to by the fact that two editions of it appeared in 1965 and by the further fact that its author is better known today than he was a century ago. Those who today insist on "freedom now at any and all costs" are the direct spiritual descendants of the North Carolina free Negro who became a secondhand clothes dealer in Boston and the author of one of the most incendiary antislavery tracts published before the Civil War. Indeed, according to the editor, the publication of Walker's Appeal . . . to the Coloured Citizens of the World did as much as "any single event to trigger the Negro revolt." David Walker was a fiery, uncompromising enemy of slavery; and it would appear that he spent more time attacking slavery—through speeches, newspaper articles, and other writings—than in dealing in used clothing and sailors' gear. Walker's Appeal may well be regarded as a significant turning point in antislavery writings—from the rather mild antislavery remonstrances by the Quakers to the strident voices raised by Garrison and his fellow crusaders. BOOK REVIEWS189 His was an "ungentle probing that first laid bare the deepseated schizophrenia of the South, where the right hand held the Bible and the left hand the bull whip." The Appeal went through three editions in 1829 and 1830; and when Walker was found dead in June 1850, in the doorway of his shop, few doubted that this eloquent voice in the battle for Negro freedom had been violently stilled. Already there was a price on his head in several southern states where even the possession of the Appeal had become a crime against the state. Thirty years ago, in the Journal of Southern History, Clement Eaton described Walker's Appeal as "A Dangerous Pamphlet in the Old South" and indicated that its appearance created extreme fear and apprehension among the southern leaders. In North Carolina the governor wrote to the police of the principal towns and to the senators of thirty-two eastern counties urging them to guard against any unfortunate consequences of the pamphlet's circulation. The next session of the General Assembly passed "An Act to Prevent the Circulation of Seditious Publications." Walker's Appeal was indeed seditious and incendiary. The editor says that it "decries hypocrisy, repudiates...

On the Dynamics of a Bull Whip

The production of a cracking sound by a bull whip is discussed. Photographic evidence shows that the crack is produced by the tip of the whip exceeding the speed of sound and giving off shock waves rather than by the whip slapping itself. This evidence includes motion pictures as well as still shadow pictures which show the tip shedding shock waves. There follows a mathematical discussion of an idealized bull whip with a view to the problem of how the free end of this mechanism achieves a high velocity while the end held in the hand moves relatively slowly. A mathematical solution is given in which it is assumed that a discontinuity in tension propagates down the whip.

On the Dynamics of a Bull Whip

It appears that this well-known device has never been discussed in the literature. The popular notion of how it produces such a loud report is that leather is made to hit upon leather. It is shown as a matter of fact that the sharp crack of the whip arises when its tip exceeds the velocity of sound, thus generating a shock wave. The motions executed by this device together with the speed multiplication produced make it an interesting mechanical contrivance