International Journal of Innovation and Scientific Research ISSN 2351-8014 Vol. 54 No. 2 May. 2021, pp. 56-63 © 2021 Innovative Space of Scientific Research Journals http://www.ijisr.issr-journals.org/ Corresponding Author: Emmalia Adriantantri 56 The reduction of bullwhip effect by Integrating Information Sharing, Forecasting, Economic Order Quantity (EOQ) - Vendor Management Inventory (VMI) - and Consignment (Cs) Approach Emmalia Adriantantri and Sri Indriani Industrial Engineering, National Institute of Technology, Malang, East Java, Indonesia Copyright © 2021 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT: This research aims to create a conceptual method, in order to reduce the effect of bullwhip by integrating information sharing, Forecasting, Economic Order Quantity (EOQ), Vendor Management Inventory (VMI), and Consignment (Cs) methods. The results are used to build an application that can be used for information sharing, simulation using forecasting, and Economic Order Quantity-Vendor Management Inventory-Consignment methods, which can reduce the effect of bullwhip. It can be concluded that through information sharing, the results obtained in the forecasting method is more accurate, because customer requests can be identified by suppliers and retailers. Also, the optimal product lot size and total cost was obtained by using the Economic Order Quantity-Vendor Management Inventory-Consignment model. These aforementioned integration steps were taken as an effort to reduce the effect of bullwhip. KEYWORDS: Bullwhip Effect, Information Sharing, EOQ, VMI-Consignment, Inventory. 1 INTRODUCTION In today's industrial world, the level of competition is getting higher, hence, companies should be able to compete in order to survive. This is because, the higher the level of competition, the more the consumers are able to benefit from the large selection of products or services available, such that they are increasingly critical about the quality of the products and services offered. Therefore, the company must be able to take strategic steps in order to compete in winning the market and achieve maximum production results to meet market demand. A strategic step that companies can take is to maintain good coordination between retailers, suppliers, and factories that form a chain called the supply chain. What often happens in the supply chain is information distortion, resulting in variations in demand, this event is called the bullwhip effect [1] According to Jiang, Q. and Ke, G. (2019), the Bullwhip effect is a situation that occurs in the supply chain where demand from customers changes. These changes can cause various impacts, thereby resulting in the disruption of the supply chain. For instance, the amount of product demand that is always changing with fixed ordering times and the lack of accurate communication will cause various kinds of disruptions to the supply chain, such as an increase and varied demand from upstream to downstream [2]. Hence, adequate research is needed to be carried out in order to solve this problem. The causes of the bullwhip effect include, the accumulation of orders, processing customer requests, waiting time for product orders to arrive, price changes, distrust from other parties, and the company's product inventory policy [4]. On the other hand, the ways to reduce this effect are, sharing information, reducing lead time, changing supply chain structures, creating price stability, and reducing costs [5]. Based on this description, it is necessary to integrate several methods that can be used to overcome the causes of this bullwhip effect. This will make products to be available in a timely manner and in quantity to meet customer demands.