developing countries and the future of the automobile industry abstract this paper reassesses the controversial view which has assumed that at some point in the future the global automobile industry having reached maturity would naturally migrate to the leading developing countries where the markets are growing more rapidly and wages are substantially lower the authors argue that the threshold facing a developing country seeking to establish a domestic automobile industry has risen because of two recent developments the rise of japan as a major automobile producer and a new wave of technological and organizational innovation this involves use of state of the art microelectronics and flexible manufacturing system as well as complete restructing of component supply resulting in considerable unit cost and lead time advantages the authors look at what these trends mean for both the oecd and the developing countries they outline the conventional view in more detail and then present an alternative analysis of the evolution of the industry new policy options for the developing countries are spotlighted

reducing the bullwhip effect looking through the appropriate lens demand amplification now frequently referred to as bullwhip is potentially a very costly phenomenon it can lead to stock outs large and expensive capacity utilisation swings lower quality products and considerable production transport on costs as deliveries are ramped up and down at the whim of the supply chain however the detection of bullwhip depends on which lens is used this in turn depends on the background and requirements of various players within the value stream to gain insight into this scenario we exploit a relatively simple replenishment model because new and novel analytic solutions have been derived for all important performance metrics comparison of the competing bullwhip measures is thereby greatly streamlined in the complex real world the likelihood is that supply chains will generate even greater inconsistency between alternative variance shock and filter lens viewpoints

international sourcing and supply chain stability an international supply chain is conceptualized as a complex dynamic system in which disruptions interact with long shipping and lead times to generate costs findings from a case study and simulation model indicate that demand related disruptions created substantial and unexpected costs in terms of expedited shipping high inventories and lower demand fulfillment production related disruptions declined over time but demand related disruptions did not implications for management are discussed

the analysis of bullwhip effect in a hmms type supply chain the aim of the paper is to investigate the well known bullwhip effect of supply chains control theoretic analysis of bullwhip effect is extensively analyzed in the literature with the laplace transform this paper tries to examine the effect for an extended holt modigliani muth simon model a two stage supply chain supplier manufacturer is studied with quadratic costs functional it is assumed that both firms minimize the relevant costs the order of the manufacturer is delayed with a known constant two cases are examined supplier and manufacturer minimize the relevant costs decentralized and a centralized decision rule the question is answered how to decrease the bullwhip effect

production chains and aggregate output volatility abstract a production chain s aggregate output volatility depends upon a number of factors including the number of firms in a chain the management strategy of the firms the point at which products are differentiated lead times and the persistence of demand shocks the influence of these factors is quantified here with an n firm model of the production chain under pure production to stock pts the firms in the chain respond simultaneously to a demand shock producing a positive covariance across firms that raises aggregate volatility under production to order pto the chain s response to a demand shock is staggered but when demand shocks are persistent there is a catch up effect that raises the volatility of each firm s production above that of a firm that under pts nevertheless pto chains typically exhibit less volatility than pts chains thanks to the covariance effect further simulations demonstrate that the production chain stabilizes as the number of production cycles in an observation period increases

the bullwhip effect in supply chains an overestimated problem abstract a phenomenon that is now well known as the bullwhip effect suggests that the variability of orders increases as they move up the supply chain from retailers to wholesalers to manufacturers to suppliers in this paper we will focus mainly on measuring the bullwhip effect existing approaches that aim at quantifying the bullwhip effect neglect the network structure of supply chains by only assuming a simple two stage supply chain consisting of a single retailer and a single manufacturer some of the relevant risk pooling effects associated with the network structure of supply chains are disregarded risk pooling effects arise when the orders which a retailer receives from its customers are statistically correlated with a coefficient of correlation less than one when analyzing the bullwhip effect in supply chains however the influence of risk pooling has to be considered the fact that these influences have not yet been analyzed motivates the research presented in this paper we will show that the bullwhip effect is overestimated if just a simple supply chain is assumed and risk pooling effects are present

the case for permissive patents whatever its shortcomings in practice until very recently patent law has sought to embody the winner takes all principle this paper argues that it is both feasible and desirable to allow multiple prizes indeed it is possible that complete abolition of the patent system by raising the returns to late finishers would yield an improvement on the current situation

on the impact of order volatility in the european automotive sector order volatility is an unfortunate fact of life facing most suppliers of both products and services in this paper we are concerned with establishing the magnitude of the problem faced by the european automotive sector the evidence has been acquired via the site based quick scan audit methodology qsam production scheduler strategy is thereby classified according to a new five set schema as observed via individual value stream volatilities system variables have then been codified and correlated with customer order volatility powerful statistically significant relationships emerge from this evidence this generally but not wholly supports intrinsic views on what constitutes good practice a specific interface between supplier and oem shows the existence of a positive loop that acts as a vicious circle to create unnecessary volatility in material flow

evaluating alternative capacity strategies in semiconductor manufacturing under uncertain demand and price scenarios abstract because product demand is very volatile and machine and process technologies are advanced at a rapid pace capacity planning and investment in the semiconductor industry is a challenging task many studies have addressed mid and short term machine portfolio planning tasks of capacity planning however capacity planning should be considered in a framework of strategy planning in order to address the whole problem this paper describes a method of analysis for adapting capacity strategy to changing business environment the paper has three major parts in the first part empirical data analysis of a case study company yields predictive formulas for production and capacity costs the uncertainty of demand is also calibrated using the geometric brownian motion process in the second part experiments are designed to simulate demand and profit scenarios for comparing two capacity strategies in the third part the resultant data of simulation are analysed to gain insights to the relative performance of the two strategies in various scenarios the analysis method provides a framework for formulating capacity strategy and for integrating capacity planning with business planning

the effect of inventory record inaccuracy in information exchange supply chains abstract the goal of this paper is to quantify the impact of inventory record inaccuracy on the dynamics of collaborative supply chains both in terms of operational performance i e order and inventory stability and customer service level to do so we model an information exchange supply chain under shrinkage errors in the inventory item recording activity of their nodes present the mathematical formulation of such supply chain model and conduct a numerical simulation assuming different levels of errors results clearly show that inventory record inaccuracy strongly compromises supply chain stability particularly when moving upwards in the supply chain important managerial insights can be extracted from this analysis such as the role of benefit sharing strategies in order to guarantee the advantage of investments in connectivity technologies

innovation in vertically related markets we examine the impact of vertical industry structure on upstream process innovation we find that vertical integration vi generally enhances innovation under downstream cournot competition but can diminish innovation under downstream bertrand competition we also find that under bertrand competition vi can increase innovation when the direct incentives for innovation are limited but can reduce innovation when the direct incentives are pronounced

on the winner take all principle in innovation races what is the optimal allocation of prizes in an innovation race should the winner take all or is it preferable that the original inventor shares the market with subsequent independent duplicators some recent papers in law and economics have argued that the latter more permissive solution is socially preferable under mild conditions we re examine that issue arguing that a permissive regime may turn the innovation race into a waiting game reducing the power of incentives and may invite socially wasteful duplicative r d expenditures in a model that accounts for these effects the winner take all system turns out to be preferable in a broad set of circumstances especially in highly innovative industries jel k11 l1 o34

a supply chain as a series of filters or amplifiers of the bullwhip effect abstract the bullwhip effect refers to the phenomenon of amplification and distortion of demand in a supply chain by eliminating or controlling this effect it is possible to increase product profitability reducing useless costs such as stock out and obsolescence costs the main focus of this work is to study a single product serial supply chain in which a control parameter can switch the chain from a series of filters to a series of amplifiers of the bullwhip effect and to analyse how the optimal values of the parameters change when discontinuities in order policy are considered furthermore it is also shown that the bullwhip itself it is not a good index of the chain s performance because it does not consider the oscillations that occur in the inventories which also may affect the supply chain performance

the production and inventory behavior of the american automobile industry understanding inventory movements is central to an understanding of business cycles this paper presents an empirical study of the behavior of inventories in the automobile industry it finds that inventory behavior is well explained by the assumption of intertemporal optimization with rational expectations the underlying cost structure appears to have substantial costs of changing production as well as substantial costs of being away from target inventory thelatter being a function of current sales given this cost structure whether inventory behavior is stabilizing or destabilizing depends on the characteristics of the demand process in the automobile industry inventory behavior is destabilizing the variance of production is larger than the variance of sales

component sourcing strategies of multinationals an empirical study of european and japanese multinationals this is a study of component sourcing decisions of european and japanese manufacturers for supplying their manufacturing operations in their home countries for export to the u s as well as their operations in the united states specifically employing data from seventy one multinational manufacturers of european and japanese origin operating in the u s the study investigated the determinants of international sourcing decisions the authors found support for the hypothesis that international sourcing could be explained using international plant location theory the significance of this finding is that it offers a new theoretical framework to spur much needed research on the topic of international sourcing

small sample uncertainty aspects in relation to bullwhip effect measurement abstract the bullwhip effect as a concept has been known for almost half a century starting with the forrester effect the bullwhip effect is allegedly observed in many supply chains and it is generally accepted as a potential malice despite this the bullwhip effect still seems to be first and foremost a conceptual phenomenon some even simply denies that the phenomenon exists at all in practice this of course makes it important to perform measurements because only what gets measured gets done as the saying goes in analytics few measurements are reported in the literature however typically based on standard statistical assumptions in the case of a standard measurement of the bullwhip effect independence amongst the participating variables are required amongst others but this is definitely known not to be perfectly true if any systematic control at all have taken place in the supply chain this paper analyses the bullwhip measurement implications in case the standard test assumptions are violated and illustrates how to improve on the testing setup this is further done with a special emphasis on the unavoidable small sample aspects relating to such measurement in practice which typically renders all statistical asymptotic or robust arguments quite unusable it is shown how h 0 95 confidence test intervals still easily can be obtained numerically in such cases

a human experiment on inventory decisions under supply uncertainty abstract controlled human experiments are adopted in this paper to investigate the impact of supply uncertainty on buyers inventory management the experiments aim at assessing the impact of one specific source of supply chain uncertainty namely stochastic lead times on inventory holdings and the extent of the bullwhip effect three experimental treatments are run within the framework of the beer game manipulating variability in demand and in lead times results confirm that the bullwhip effect arises in all experimental treatments and that the variance of orders is higher under stochastic lead times analysis of players behaviour in the course of the game suggests that players react to higher uncertainty by holding fewer inventories a behaviour consistent with the predictions of some psychological models of choice under ambiguity

information distortion in a supply chain the bullwhip effect this article originally appeared in management science april 1997 volume 43 number 4 pp 546 558 published by the institute of management sciences consider a series of companies in a supply chain each of whom orders from its immediate upstream member in this setting inbound orders from a downstream member serve as a valuable informational input to upstream production and inventory decisions this paper claims that the information transferred in the form of orders tends to be distorted and can misguide upstream members in their inventory and production decisions in particular the variance of orders may be larger than that of sales and distortion tends to increase as one moves upstream a phenomenon termed bullwhip effect this paper analyzes four sources of the bullwhip effect demand signal processing rationing game order batching and price variations actions that can be taken to mitigate the detrimental impact of this distortion are also discussed

closed loop supply chains what reverse logistics factors influence performance this paper analyses the inventory and order flow dynamics in closed loop supply chains clscs in this kind of supply chains the reverse flow of materials entering the system for recycling purposes complicates the way in which inventories should be managed and replenishment policies should be designed specifically we analyse the relationships between some reverse logistics factors remanufacturing lead time return rate of recycled products reverse order policy and number of supply chain tiers on the order and inventory variance amplification we firstly perform a systematic literature review of the related studies secondly by adopting a difference equation math approach and design of experiment we perform a robust what if analysis of a clsc under a variety of operational and market conditions results show that ceteris paribus clsc outperforms a forward supply chain both in mono echelon and multi echelon structures and under both stationary and turbulent market demands furthermore reducing remanufacturing lead time and promoting information transparency may be crucial to improve clsc dynamics finally we use the research findings to provide interesting managerial consideration about how to reduce unnecessary operational members costs

the bullwhip effect progress trends and directions the bullwhip effect refers to the phenomenon where order variability increases as the orders move upstream in the supply chain this paper provides a review of the bullwhip literature which adopts empirical experimental and analytical methodologies early econometric evidence of bullwhip is highlighted findings from empirical and experimental research are compared with analytical and simulation results assumptions and approximations for modelling the bullwhip effect in terms of demand forecast delay replenishment policy and coordination strategy are considered we identify recent research trends and future research directions concerned with supply chain structure product type price competition and sustainability

the role of forecasting on bullwhip effect for e scm applications abstract the bullwhip effect represents the information distortion in customer demand between orders to supplier and sales to the buyer demand forecasting is one of the main causes of the bullwhip effect the purpose of this study is to analyze the impact of exponential smoothing forecasts on the bullwhip effect for electronic supply chain management e scm applications a simulation model is developed to experiment the different scenarios of selecting right parameters for the exponential smoothing forecasting technique it is found that longer lead times and poor selection of forecasting model parameters lead to strong bullwhip effect in e scm in contrast increased seasonality helps to reduce the bullwhip effect the most significant managerial implication of this study lies in the need to reduce lead times along the e supply chain to mitigate the bullwhip effect while high seasonality would reduce the forecast accuracy it has a positive influence on the reduction of bullwhip effect e scm managers are therefore strongly suggested to utilize exponential smoothing by selecting lower values for and and a mid value for to keep the bullwhip ratio low while at the same time to increase forecast accuracy

secrecy versus patenting we develop an equilibrium search model of innovation with the possibility of multiple independent discovery we distinguish innovations from ideas and we view patents as probabilistic property rights that are constrained by the innovators option to keep the innovation secret we find that the patent system can simultaneously stimulate innovation information disclosure and welfare an optimal patent may provide more or less protection than secrecy and in many cases it provides less suggesting that its main function is information spreading rather than rewarding the costs of the innovative activity

transfer function analysis of forecasting induced bullwhip in supply chains the present paper analyses the bullwhip problem generated by exponential smoothing algorithms in both stand alone passing on orders mode and within inventory controlled feedback systems results are predicted from transfer function analysis and then confirmed by simulation via the bullwhip explorer supply chain software a novel feature of the paper is the introduction of the matched filter concept into the exponential smoothing algorithm this adjusts the value of the smoothing constant depending on whether the constant linear or quadratic forecasting model is used it is shown that matching the filter via noise bandwidth equalises the output variance when the demand is a random signal hence some of the unwanted effects of using the linear and quadratic forecasting models are attenuated however there is little benefit obtained by using sophisticated forecasting methods within inventory controlled feedback systems as their tracking ability is reduced

market structure incentive to patent and the pace of innovation abstract in a model of sequential innovations it is shown that the simple monotone relationship between the number of firms and the speed of innovation see e g loury 1979 no longer holds if we explicitly take account of the incentive to patent

joint production and pricing decisions with setup costs and capacity constraints we consider the problem of setting prices and choosing production quantities for a single product over a finite horizon for a capacity constrained manufacturer facing price sensitive demands there is a fixed cost per production run and a variable cost per unit produced both of which may vary by period we characterize properties of the optimal solution considering cases with constant and time varying capacity and with and without speculative motive for holding inventory we show that counter to intuition optimal prices may increase as the capacity increases even when capacity is constant over the horizon we also show that increases in capacity do not always exhibit diminishing marginal returns our procedure produces solutions with much higher profits than can be obtained from a sophisticated sequential procedure in which a well informed and optimum seeking marketing department makes pricing decisions and the manufacturing department seeks to satisfy the resulting demands at minimum cost our results also suggest that firms with seasonal demand and tight capacity constraints should be more aggressive in setting prices to manage their demands than what is typically done in practice finally we discuss how a decision maker can use our procedure as an aid in solving multiproduct versions of the problem

prior user rights author s shapiro carl abstract keywords patents innovation oligopolyjel codes l13 o31 abstract many inventions great and small are discovered independently at roughly the same time by two or more individuals or organizations famous examples include the light bulb edison and swan the telephone bell and gray and the integrated circuit kilby and noyce such independent invention is common for minor technological improvements how should property rights to an invention be defined and awarded in such cases patent law has struggled with this question for many years the basic rule in the u s is that the patent is awarded to the first firm to invent later independent inventors come up empty handed however this basic system can create some peculiar results suppose that firm a achieves an invention and files for a patent slightly later but before the invention is made public firm b independently discovers the same invention firm a receives the patent and can even prevent firm b from practicing its own invention in legal terms a party accused of patent infringement cannot defend itself by showing that it discovered the same invention independently would such an independent invention defense be desirable alternatively suppose that firm a achieves an invention but decides not to file for a patent perhaps because firm a does not believe this invention is sufficiently novel and non obvious to be patentable instead firm a uses the invention internally in its own operations as a trade secret later firm b independently discovers the same invention and files for a patent under current u s patent law firm b is awarded the patent because firm a kept its invention secret

a note on a multi period profit maximizing model for retail supply chain management in this note we present an efficient exact algorithm to solve the joint pricing and inventory problem for which bhattacharjee and ramesh 2000 proposed two heuristics the algorithm is based on a method proposed by thomas 1970 and we show additional properties which can be used to arrive at an even more efficient algorithm furthermore we point out several shortcomings in the paper by bhattacharjee and ramesh

managing the trade off implications of global supply abstract the cost versus response trade off is a growing logistics issue due to many markets being increasingly characterised by demand uncertainty and shorter product life cycles this is exacerbated further with supply increasingly moving to low cost global sources however the poor response implications of global supply are often not addressed or even acknowledged when undertaking such decisions consequently various practical approaches to minimising postponing or otherwise managing the impact of the demand uncertainty are often only adopted retrospectively even though such generic solutions are documented through case examples we lack effective tools and concepts to support the proactive identification and resolution of such trade offs this paper reports on case based theory building research involving three cases from the uk and usa used in developing a conceptual model with associated tools in support of such a process

inventory performance under pack size constraints and spatially correlated demand abstract motivated by a problem facing a large retailer we consider the impact of pack size on the performance of a periodic review inventory system in the presence of spatial i e between retailers correlation of demand which we model using an equicorrelated multivariate poisson distribution employing simulation we utilise a full factorial experiment to provide support for decisions on product and supplier selection and whether or not packs should be split during distribution we consider variables such as pack size correlation and the number of branches and discuss how they and their interactions impact performance metrics such as inventory and shortage levels and the bullwhip effect

an empirically simulated investigation of the impact of demand forecasting on the bullwhip effect evidence from u s auto industry this study empirically examines the impacts of three major aspects of demand forecasting on the magnitude of the bullwhip effect three research questions are addressed to investigate the association between 1 forecast accuracy 2 aggregate forecasting and 3 responsive forecasting and the bullwhip effect using forecasted demand generated from popular time series forecasting models and real life demand data the study investigates the relationship between the forecasted results and the consequential bullwhip effect the findings show that the forecasting methods used lead to the variation of the bullwhip effect moreover the lead time reduction and the stable demand forecast are beneficial to reduce the bullwhip effect however our empirical results differ from previous findings in two ways i improving forecast accuracy does not necessarily reduce the bullwhip effect and ii aggregate forecasting does not always reduce the bullwhip effect

the impact of information enrichment on the bullwhip effect in supply chains a control engineering perspective this paper examines the beneficial impact of information sharing in multi echelon supply chains we compare a traditional supply chain in which only the first stage in the chain observes end consumer demand and upstream stages have to base their forecasts on incoming orders with an information enriched supply chain where customer demand data e g epos data is shared throughout the chain two types of replenishment rules are analysed order up to out policies and smoothing policies policies used to reduce or dampen variability in the demand for the class of out policies we will show that information sharing helps to reduce the bullwhipeffect variance amplification of ordering quantities in supply chains significantly especially at higher levels in the chain however the bullwhip problem is not completely eliminated and it still increases as one moves up the chain for the smoothing policies we show that information sharing is necessary to reduce order variance at higher levels of the chain the methodology is based on control systems engineering and allows us to gain valuable insights into the dynamic behaviour of supply chain replenishment rules we also introduce acontrolengineering based measure to quantify the variance amplification bullwhip or variance reduction

sourcing strategies of european and japanese multinationals a comparison based on a typology of sourcing strategies this study identifies various sourcing patterns adopted by european and japanese multinational manufacturing firms in serving the u s market the study has found that the product s market performance is not at all related to its life cycle stage in world trade or to production location but is positively related to the internal components sourcing and negatively related to the product adaptation the findings strongly support levitt s call for a global product

the extension and exploitation of the inventory and order based production control system archetype from 1982 to 2015 in 1994 through classic control theory john naim and towill developed the automatic pipeline inventory and order based production control system apiobpcs which extended the original iobpcs archetype developed by towill in 1982 well recognised as a base framework for a production planning and control system due to the prevalence of the two original models in the last three decades in the academic and industrial communities this paper aims to systematically review how the iobpcs archetypes have been adopted exploited and adapted to study the dynamics of individual production planning and control systems and whole supply chains using various databases such as scopus web of science google scholar 111 papers we found that the iobpcs archetypes have been studied regarding the a modification of four inherent policies related to forecasting inventory lead time and pipeline to create a family of models b adoption of the iobpcs family to reduce supply chain dynamics and in particular bullwhip c extension of the iobpcs family to represent different supply chain scenarios such as order book based production control and closed loop processes simulation is the most popular method adopted by researchers and the number of works based on discrete time based methods is greater than those utilising continuous time approaches most studies are conceptual with limited practical applications described future research needs to focus on cost flexibility and sustainability in the context of supply chain dynamics and although there are a few existing studies more analytical approaches are required to gain robust insights into the influence of nonlinear elements on supply chain behaviour also empirical exploitation of the existing models is recommended

demand fluctuation and chaotic behaviour by interaction between customers and suppliers this paper presents an investigation on simulation of interaction between customers and suppliers in a three tier supply chain system in the simulation customers respond to the price discount offer made by the supplier and the supplier makes adjusts the price according to stock held the simulation shows that the behaviour of such interaction exhibits deterministic chaos it is found that the attractors of the model move with the environment and the initial states thus the bifurcating points in such a system are unable to provide a guideline in system design to avoid chaos

a novel time varying bullwhip effect metric an application to promotional sales abstract bullwhip effect is a problem of paramount importance that reduces competitiveness of supply chains around the world a significant effort is being devoted by both practitioners and academics to understand its causes and to reduce its pernicious consequences nevertheless limited research has been carried out to analyse potential metrics to measure it that typically are summarized in the coefficient of variation ratio of different echelons demand this work proposes a new metric based on a time varying extension of the aforementioned bullwhip effect metric by employing recursive estimation algorithms expressed in the state space framework to provide at each single time period a real time bullwhip effect estimate in order to illustrate the results a case study based on a serially linked supply chain of two echelons from the chemical industry is analysed particularly this metric is employed to analyse the effect of promotional campaigns on the bullwhip effect on a real time fashion the results show that effectively the bullwhip effect is not constant along time but interestingly it is reduced during the promotional periods and it is bigger before and after the promotion takes place

rogue seasonality detection in supply chains rogue seasonality or unintended cyclic variability in order and other supply chain variables is an endogenous disturbance generated by a company s internal processes such as inventory and production control systems the ability to automatically detect diagnose and discriminate rogue seasonality from exogenous disturbances is of prime importance to decision makers this paper compares the effectiveness of alternative time series techniques based on fourier and discrete wavelet transforms autocorrelation and cross correlation functions and autoregressive model in detecting rogue seasonality rogue seasonalities of various intensities were generated using different simulation designs and demand patterns to evaluate each of these techniques an index for rogue seasonality based on the clustering profile of the supply chain variables was defined and used in the evaluation the fourier transform technique was found to be the most effective for rogue seasonality detection which was also subsequently validated using data from a steel supply network

patenting in the shadow of independent discoveries by rivals abstract this paper studies the decision of whether to apply for a patent in a dynamic model in which firms innovate stochastically and independently in the model a firm can choose between patenting and maintaining secrecy to protect a successful innovation i consider a legal environment characterized by imperfect patent protection and no prior user rights thus patenting grants probabilistic protection and secrecy is effectively maintained until rivals innovate i show that 1 firms that innovate early are more inclined to choose secrecy whereas firms that innovate late have a stronger tendency to patent 2 the incentives to patent increase with the innovation arrival rate and 3 an increase in the number of firms may cause patenting to occur earlier or later depending on the strength of patent protection the socially optimal level of patent protection which balances the trade off between the provision of patenting incentives and the avoidance of deadweight loss caused by a monopoly is lower with a higher innovation arrival rate or a larger number of firms

quantifying the bullwhip effect using two echelon data a cross industry empirical investigation the bullwhip effect denotes the phenomenon whereby demand variability is amplified from a downstream site buyer to an upstream site supplier in the supply chain this paper contributes to the literature that empirically investigates the bullwhip effect by providing new evidence regarding its prevalence and magnitude in contrast to previous work we use a two echelon approach which allows us to observe variations at both the upstream and the downstream sites by drawing on a financial accounting standard regarding information disclosure about major customers we are able to link 5494 buyers and suppliers in the u s between 1976 and 2009 we merge this information with quarterly financial accounting data to form a sample of 14 933 buyer supplier dyad observations we correct for sample selection bias using propensity score matching and estimate the average bullwhip effect in our sample to be 1 90 i e 90 demand variability amplification between echelons a significant bullwhip effect is observed across industries mining manufacturing wholesale and retail and is supported by several robustness checks we investigate and discuss how these results can be generalized beyond our sample

requirements planning with pricing and order selection flexibility past requirements planning research has typically assumed that the firms demands are determined prior to production planning in contrast we explore a single stage planning model that implicitly decides through pricing decisions the demand levels the firm should satisfy in order to maximize contribution to profit we briefly discuss solution methods and properties for these problems when production capacities are unlimited the key result of this work is a polynomial time solution approach to the problem under time invariant finite production capacities and piecewise linear and concave revenue functions in price

international manufacturing strategies of u s multinationals a conceptual framework based on a four industry study drawing upon complementary streams of research from the international production and manufacturing strategy literature a conceptual framework was developed that identifies the major internal and external factors that may influence a firm s international manufacturing configuration imc decisions the framework was then examined using sixteen companies drawn from four distinct industry sectors the findings indicate that a firm s competitive priorities expressed as the differential emphasis placed on four key manufacturing performance priorities in addition to other key variables such as market orientation experience and product characteristics play important roles in the development of imc strategies

simultaneous model of innovation secrecy and patent policy multiple innovators can and do come up with the same invention independently a famous case is the telephone two hours after alexander graham bell filed a patent application for it another application for the same invention arrived at the patent office many scholars such as ilkka rahnasto 2003 and hal r varian et al 2004 argue that since bell s time simultaneous innovation has become increasingly common we feel and our discussions with industry practitioners confirm that the simultaneous model of innovation characterizes especially network industries such as consumer electronics the internet software telecommunications and payment systems where standardization limits the possible paths for future technologies and so firms concentrate their r d activities on the same fields we suggest that simultaneous or independent invention has major implications for intellectual property ip policy in particular the possibility of simultaneous innovation changes the patenting decision firms tap patents for a defensive purpose since the choice is no longer between patenting or resorting to trade secrecy but between patenting or letting competitors patent by exploiting the vulnerability of innovative firms to rival innovation it is possible to design a welfareimproving patent system that induces innovators to patent rather than keep their innovations secret taking the simultaneous nature of innovation seriously also changes the way one should think about the relationship between ip and competition policies

on bullwhip in supply chains historical review present practice and expected future impact abstract demand amplification or bullwhip as it is now called is not a new phenomenon since evidence of its existence has been recorded at least as far back as the start of the 20th century and is well known to economists yet industry worldwide still has to cope with bullwhip measured not just in terms of the 2 1 amplification which is frequently quoted but sometimes it is as high as 20 1 from end to end in the supply chain this can be very costly in terms of capacity on costs and stock out costs on the upswing and stockholding and obsolescence costs on the downswing in this paper we have identified 10 published causes of bullwhip all of which are capable of elimination by re engineering the supply chain we offer evidence on the present health of a family of supply chains and pinpoint much good practice this is in anticipation that such excellence will become normative in the near future as the learning experience gathers momentum and provided that human factors are properly addressed

offshore sourcing reaction maturation and consolidation of u s multinationals the authors conducted a quasi longitudinal investigation of u s multinationals r d manufacturing offshore sourcing strategies and resultant global market performance implications utilizing comprehensive data collected by the 1977 1982 and 1989 benchmark surveys of u s direct investment abroad hypotheses were tested in a path analytic framework despite increased competition at home and abroad causing their global market share positions to weaken in recent years u s multinationals have maintained and even may have improved their global consolidated profitability levels by skillfully exploiting their technological prowess through technology transfer and off shore sourcing rapidly changing roles of u s parent firms and their foreign affiliates in technology development and global sourcing relationships portend a maturing yet arduous shift toward a global rationalization

the effect of replenishment policies on the bullwhip effect a transfer function approach an important phenomenon in supply chain management known as the bullwhip effect suggests that demand variability increases as one moves up a supply chain this paper examines the influence of different replenishment policies on the occurrence of the bullwhip effect the paper demonstrates that certain replenishment policies can in themselves be inducers of the bullwhip effect while others inherently lower demand variability the main causes of increase in variability are projections of future demand expectations which result in over exaggerated responses to changes in demand we suggest that through appropriate selection and use of certain replenishment rules the bullwhip effect can be avoided subsequently allowing supply chain management costs to be lowered

dynamic version of the economic lot size model this article originally appeared in management science october 1958 volume 5 number 1 pp 89 96 published by the institute of management sciences a forward algorithm for a solution to the following dynamic version of the economic lot size model is given allowing the possibility of demands for a single item inventory holding charges and setup costs to vary over n periods we desire a minimum total cost inventory management scheme which satisfies known demand in every period disjoint planning horizons are shown to be possible which eliminate the necessity of having data for the full n periods

patent litigation as an information transmission mechanism patent litigation reveals important information about the validity of the contested patent to other potential entrants this paper explores the implications of such informational externalities for entry dynamics in the presence of multiple potential entrants the nature of the entry game can be one of either waiting or preemption depending on the degree of patent protection therefore the payoffs for the patentee and the initial imitator are discontinuous in the degree of patent protection furthermore strengthening intellectual property rights is not necessarily desirable for the patentee the analysis may also help explain the apparently puzzling practice of delaying patent suits copyright 1998 by american economic association

a pragmatic approach to the design of bullwhip controllers it is well known that forecasting mechanisms can greatly increase bullwhip demand variance amplification of orders as processed by both human and algorithmic decision makers this paper is concerned with the application of the well established apiobpcs decision support system a variant of the order up to rule in such circumstances it has two feedback controls based on the inventory and the orders in pipeline respectively with gains set equal according to the deziel eilon rule there is one feed forward control based on exponential forecasting although this is not a restriction on the application of this system we consider the pragmatic role of apiobpcs in the situation where the echelon decision maker may be handling a wide range of sku s in a non altruistic environment where upmarket information may either be withheld or simply unavailable under such circumstances it has been established via site based studies that the decision makers output the orders reflect a wide range of strategies or maybe ignorance three strategies may be regarded as appropriate i e pass orders along demand smoothing and level scheduling depending on context apiobpcs can be adapted to each of these modus operandi in the first case with the added capability of smoothing the sharp edges with a modicum of inventory variation and in the last case with the advantage of built in trend detection players in non altruistic supply chains must be able to cope with added uncertainties due to lead time variations we show that apiobpcs may be well matched to such situations and is hence copable as well as capable the paper includes recommended parameter settings according to desired decision making policies

the relationship between offshore sourcing and innovativeness of u s multinational firms an empirical investigation in increasingly complex global competition u s multinational firms have stepped up imports under items 806 30 and 807 00 of the tariff schedules of the united states as a part of offshore sourcing of components and finished products to serve the u s market

measuring and avoiding the bullwhip effect a control theoretic approach an important contributory factor to the bullwhip effect i e the variance amplification of order quantities observed in supply chains is the replenishment rule used by supply chain members first the bullwhip effect induced by the use of different forecasting methods in order up to replenishment policies is analysed variance amplification is quantified and we prove that the bullwhip effect is guaranteed in the order up to model irrespective of the forecasting method used thus when production is inflexible and significant costs are incurred by frequently switching production quantities up and down order up to policies may no longer be desirable or even achievable in the second part of the paper a general decision rule is introduced that avoids variance amplification and succeeds in generating smooth ordering patterns even when demand has to be forecasted the methodology is based on control systems engineering and allows important insights to be gained about the dynamic behaviour of replenishment rules