Forecasting demand in the supply chain based is on only numbers of orders instead of real quantities demanded by end customers in supply chain, can lead to discrepancy between forecasted and real quantities and that discrepancy is increasing with every new participant in the supply chain. This phenomenon, where every new participant in supply chain gets increasingly wrong information about demand is known as „bullwhip effect“. In an attempt to reduce these irregularities manufacturers oblige distributors to deliver forecasted demand data on their market.This paper presents application of demand-forecasting methods as a major topic of the final thesis. Also, types of stock, individual stock levels, inventory planning and management methods, inventory control and demand calculation using time series method is also presented and elaborated.