Search results for "Bullwhip effect"
showing 9 items of 19 documents
Modelling the Bullwhip Effect Dampening Practices in a Limited Capacity Production Network
2009
This work infers on the conjoint adoption of collaboration practices and replenishment rules as bullwhip dampening techniques in a limited capacity production network. Continuous time differential equation methodology is adopted to model three supply chain configurations. Results show that theconditio sine qua non for long-term capacity strategy is the management and control of information asynchronies, provided by collaboration practices and ad-hoc decision policies. Furthermore the study reveals the phenomenon of bullwhip rough dampening.
Avoiding Demand Amplification Phenomenon via Hi-tech Application: A What-If Supply Chain Analysis
2010
The well-known deleterious effect of the amplification of variance of order rates in multi-echelon systems, commonly known as demand amplification phenomenon or bullwhip effect, still presents new challenges and continues to fascinate the operations management community. Recently this research field is focusing on the study of robustness of bullwhip avoidance techniques under uncertainty, as environmental conditions often determine variations in processes, with regards to production and delivery lead time, and variations in the parameters of the decision policies. This work aims at quantifying the efficacy of bullwhip dampening techniques and at verifying this efficacy against variations in…
The Impact Of Demand And Inventory Management Policies On Bullwhip Effect In Production Networks
2004
The bullwhip effect is a phenomenon consisting in variance amplification of orders as they move up a supply chain. The immediate bullwhip effect consequences are the increase of inventory costs, poor custoiner services and inefficient utilization of resources due to the difficulties of production planning activities in highly variable conditions. There are many factors that cause the bullwhip effect, but if is particularly due to demand forecasting and inventory management policies. In this paper the impact on bullwhip effect of different policies to manage demand and inventories has been evaluated through discrete event simulation, using the ARENA (R) simulation package.
Closed-loop supply chains: What reverse logistics factors influence performance?
2016
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…
Capacity constrained supply chains: a simulation study
2008
This paper explores the relationship between constrained capacity and supply chain performance. Six capacity constraint levels are studied under different inventory policies and information sharing strategies. The results suggest that an increment of production capacity, used in industry as local approach to manage increasing incoming orders, does not necessarily imply an improvement in customer service. In presence of information distortions, the strategy of augmenting production capacity can lead to satisfy at a higher cost an over-estimated market demand. The collaborative practices provide bullwhip effect dampening and inventory stability, and increase the ability of the structure to av…
Impact of reverse logistics on supply chain performance
2013
Purpose – The purpose of this paper is to analyse the impact of reverse logistics on order and inventory variance amplification in a single-echelon supply chain (SC) and to propose a new order policy for dampening such amplification. Design/methodology/approach – A general review of the literature on sustainable operations and on the impact of reverse logistics on SC performance provides the foundation for the study. The authors use difference equation math approach for modelling and analysing a closed SC. A proper design of experiment and data collected from the European Union statistics validate the obtained numerical results. Findings – The variability of reverse flow in a closed loop S…
Up-to-Date Supply Chain Management: The Coordinated (S, R) Order-Up-to
2011
This paper presents the mathematical derivation of a new generation of the most largely used periodic review policy in supply chain: the coordinated (S, R) replenishment rule. We first derive the classical order-up-to model and then we modify it to generate the coordinated decision policy equations. We run a numerical simulation on a serial supply chain model to show differences in the two policies. We conclude on the managerial implications related to coordinated replenishment.
Information Exchange Supply Chain under inventory inaccuracy: a simulation study
2012
The objective of this paper is to contribute at quantifying the impact of inventory record inaccuracy on operational performance and customer service level in collaborative supply chains. To this purpose we analyse the impact of shrinkage errors in the inventory item recording activity in an “information exchange supply chain”, i.e. a supply chain in which companies share information about market demand and use such information for placing orders to their suppliers. We present the mathematical formulation of such a supply chain model and we conduct a numerical simulation and a sensitivity analysis over different level of errors.
Current economic downturn and supply chain: The significance of demand and inventory smoothing
2014
The aim of this article is to analyse and quantify the effects of demand and inventory smoothing into supply-chain performance, facing the extreme volatility and impetuous alteration of the market produced by the current economic recession. To do so, we model a traditional serial three-stage supply chain and we test five settings of order smoothing under two shocks in the market demand, and we measure effects in terms of internal process benefits and customer service level of all supply chain partners. Results show that the implementation of this inventory strategy should be based on reward schemes; in fact a higher level of smoothing can generally improve the performance of the upstream st…