An analysis of the main factors affecting bullwhip in reverse supply chains

The bullwhip effect has drawn the attention of supply chains researchers due to the inefficiencies that this phenomenon generates upstream in the supply chain. Various factors that facilitate its appearance have been identified in the literature. However, in spite of current practices and new environmental regulations having increased the importance of returned material chains, this phenomenon has not been studied in detail in the context of closed loop networks. Here we present an analysis of the influence of factors identified as significant with regard to the bullwhip effect in forward chains on the appearance of the bullwhip effect in environments of reverse logistics and its pattern of evolution along the chain. We do so by using a simulator that extends the logic of the Beer Game to this type of environment. The results confirm the influence of the majority of the factors considered, especially the stock and WIP adjustment controllers, as well as the forecasting technique used, the sharing of information among the links, and the final customer demand variability. With respect to specific reverse supply chains factors, the only significant one identified is the percentage of units returned. We have also studied the factors that in this closed loop environment give rise to the classical upstream growing pattern of the bullwhip effect, observing that an increase in the percentage of material returned reduces the likelihood of finding a growing bullwhip pattern. In addition, it is more likely for this pattern to appear when the demand variation is low.