Collaborative Research: Behavioral Causes of Information Distortion in Supply Chains

事实证明，管理供应链容易出现系统性错误，而这些错误往往会导致严重的失灵。例如，石油和天然气钻探的波动是实际石油产量的三倍，对机床的需求至少是汽车销售的两倍(汽车行业是机床的主要消费者)，半导体的生产比整个工业生产的变量要大得多(Sterman 2000，第666-667页)。这种“振荡、放大和相位滞后”的模式，统称为牛鞭效应，在个别公司的供应链中也已被注意到(见Lee等人。2000年)，以及在实验室斯特曼(1989)。斯特曼的结果表明，即使在相对简单的实验室环境中，个人的行为也不是最优的，而是严重低估了他们已经订购但尚未到达的库存(称为供应线)。他总结道：“改善业绩的关键在于个人用来管理系统的政策，而不是外部环境。即使是一个完美的预测，也无法阻止忽视供应线的经理过度订购。”(斯特曼，第336页)牛鞭效应代价高昂，因为它导致库存过多，客户服务质量差，以及不必要的资本投资。我们将牛鞭效应的原因分为依赖于参与者自身的认知局限性、他们无法确定调整库存头寸的最佳方式的解释，以及依赖于协调、参与者对他人能力或行动的信念的解释。我们提议进行的实验将使用有四个参与者的传统供应链和供应链，其中一个人类参与者扮演其中一个角色，其他三个角色由编程(和已知)以最佳方式行动的计算机化代理扮演。如果偏离最佳行为是由个体的认知引起的，那么在对所有人类受试者的治疗中，行为应该与对一个人类受试者的相同。相反，如果行为是由个人对供应链合作伙伴所做决策的信念引起的，那么在处理所有人类受试者时，行为应该更糟糕。我们的研究结果可能会对企业资源规划(ERP)软件中应该包括的决策支持工具的类型产生潜在的广泛影响。如果牛鞭效应的行为原因比最近对减少运营原因的关注更重要，那么充其量只能提供一个不完整的解决方案。哪些信息或工具可以有效地缓解牛鞭效应的行为原因，这一问题尚未在文献中得到解决，我们希望这项研究将为这一新的研究议程打开大门。

Managing a supply chain has been shown to be prone to systematic errors that often lead to spectacularly dysfunctional outcomes. For example, the drilling for oil and gas fluctuates three times more than the actual petroleum production, the demand for machine tools is at least twice as variable as automobile sales (the auto industry being the main consumer of machine tools), and the production of semiconductors is much more variable than industrial production as a whole (reported in Sterman 2000, pp. 666-667). This pattern of "oscillation, amplification, and phase lag," known collectively as the bullwhip effect, has been also noted in individual firms' supply chains (see Lee et al. 2000), as well as in the laboratory Sterman (1989). Sterman's results demonstrated that individuals do not act optimally even in the relatively simple laboratory setting, but significantly underweight inventory they already ordered that has not yet arrived (called the supply line). He concluded, "the key to improved performance lies within the policy individuals use to manage the system and not in the external environment. Even a perfect forecast will not prevent a manager who ignores the supply line from over ordering." (Sterman 1989, p. 336).The bullwhip effect is costly because it causes excessive inventories, poor customer service, and unnecessary capital investment. We separate explanations of the causes of the bullwhip effect into those that rely on participants' own cognitive limitations, their inability to determine the optimal way to adjust their inventory position, and those that rely on coordination, participants' beliefs about others' abilities or actions. The experiments we propose to conduct will be using both traditional supply chains with four participants and supply chains where a human participant plays one of the roles, and the other three roles are played by computerized agents programmed (and known) to act optimally. If deviations from optimal behavior are caused by an individual's cognitions, behavior should be the same in the treatments with all human subjects as with one human subject. If instead, behavior is being caused by an individual's beliefs about the decisions his supply chain partners make, behavior should be worse in treatments with all human subjects.The results from our study can have potentially broad implications on the type of decision support tools that should be included in Enterprise Resource Planning (ERP) software. If behavioral causes of the bullwhip effect are important than the recent focus on reducing operational causes provides at best an incomplete solution. The question of what information or tools can be effective in mitigating behavioral causes of the bullwhip effect has not been addressed in the literature, and it is our hope that this study will open the door to this new research agenda.