Evaluating the effect of demand forecasting on inventory managment and identifying the co-factor variablesrnthat alter the inventory may influence the overall supply chain performance. The purpose of this researchrnis to find the main factors and viable solution that affect the effectiveness of demand forecasting inrninventory of Ethiopian agricultural business corporation. This study was performed in collaboration withrnthe Ethiopian agricultural business corporation, which provided its sales and inventory data from 20112019.rnDatarncollectedrnbyrninterview,rnquestionersrn&rndocumentsrnsurvey.rnAlso,rnanalyzedrnwithrnSPSSrnandrnMSExcelrnsoftware.rnAccordingrntornthernfindingrnofrnthernstudyrnitrnisrnverifiedrnthatrn90.2%rnofrneffectivenessrnofrnthernforecastrnrnisrnrndepends on proper mathematical forecasting model, competency of inventory staff, consideration ofrncompetitor level, economic viewpoint, the price, type and level of technology of items and the accuracy ofrninventory recording and the other 9.8% explained by other variables outside this research framework. Otherrnpublic enterprise can use the findings presented here in to drive their inventory and facility planningrndecisions and support investments in warehouse and supply chain integration.