forecast are wrong, because of some factors that may occur during the forecasting period. This factors may include, promotion, when company advertise their product without pla
…nning for the number of customer they can get during this period, even though, they have planned for the product to be sold during this period, there will still be an error in the forecast, because they may eventually get more customer or low customer.Also introduction of new product may make a forecast to be wrong since there is no historical data, that may suggest what the demand has been in the past, with this forecast may be wrong. Another reason is that customer may not want to buy the product again, this may due to fact that they have alternative product or a product that the price is reduced from the competitor, and if the customer did not buy the product,it will make the forecast to be wrong. One final point is that, unexpected event may make the forecast to be wrong. for example, it is believe that between December and November in the UK, snow must fall, if for a particular year there is no snow and a company has prepared to sell worm cloth, what would happen to that company during the period that snow does not fall,there forecast will definitely be wrong and they may loss. (MORE) 
