supply chain management is one of the main factors of successful organization. one of the important causes of its’ ineffectiveness is “bullwhip effect”. most of previous studies were about its’ effect on one-product and two-echelon chains. in this paper, the authors try to study bullwhip effect on two and three-echelon chains which includes more than one product according to some assumptions. t...

This paper compares the bullwhip properties of a Vendor Managed Inventory (VMI) supply chain with those of a traditional “serially-linked” supply chain. The emphasis of this investigation is the comparative impact the two structures have on the “Bullwhip Effect” generated. Particular attention is paid to the manufacturer’s production ordering activities as demonstrated using a simulation model ...

A simple system dynamics model of a traditional/closed loop supply chain system is investigated. Particularly, the effect of remanufacture, remanufacturing lead-time and the return rate on the inventory variance and bullwhip effect were studied. Our results clearly showed that the bullwhip in the closed loop supply chain is bigger than one in traditional supply chain and foreign to the collecti...

This paper presents a computational intelligence approach for coping with bullwhip effect in supply chains (SCs). An imperialist competitive algorithm (ICA) is employed to decrease the bullwhip effect and cost (inventory, ordering and production) in the MIT beer distribution game. The ICA is used to determine the optimal ordering policy for members of the SC. The results shows the ability of th...

one of the most important issues in the supply chain management is reducing the bullwhip effect. the bullwhip effect is the increasing of the fluctuation of demands from customer toward supplier in a supply chain. the reasons for this effect and the solution for its elimination are studied by many researchers up to now. one of the main known reasons is variation of the time value of money that ...

The impact of fast moving items, modeled by auto-regressive moving average (ARMA) type processes, on the bullwhip effect is well known. However, slow moving items that can be modeled using integer ARMA processes have received little attention. Herein, we measure the impact of bullwhip effect under a first order integer auto-regressive, INAR(1), demand process. We consider a simple two-stage sup...

Consider multiple companies operating as a serial supply chain. Within this environment, end users form the demand for the last company in the supply chain, but the demand for upstream companies is formed by the companies in the immediate downstream supply chain link. It has been shown that demand seasonality and forecast error can increase as we proceed up the supply chain. These demand distor...

bullwhip effect phenomenon is what reduces the efficiency of the supply chain. the effect occurs when demand changes in the supply chain face with a lot of volatility. so far, several key factors have been identified as causes of this phenomenon. since the steel industry, is the basic one, its efficiency is of great importance. therefore, in this study influencing factors on bullwhip effect in ...

This paper introduces the confidence interval estimate for measuring the bullwhip effect, which has been observed across most industries. Calculating a confidence interval usually needs the assumption about the underlying distribution. Bootstrapping is a non-parametric, but computer intensive, estimation method. In this paper, a simulation study on the behavior of the 95% bootstrap confidence i...

this paper explains a model for analyzing and measuring the propagation of order amplifications (i.e. bullwhip effect) for a single-product supply network topology considering exogenous uncertainty and linear and time-invariant inventory management policies for network entities. the stream of orders placed by each entity of the network is characterized assuming customer demand is ergodic. in fa...