Abstract
From the bible and the predictions of God to the Oracle of Delphi, Merlin or the Chinese I-ching people have been always fascinated in knowing the future and predicting it. Those lights opened on the future were used to prevent the change of climate in the prehistoric times or to determine if it was the ideal moment to go to make war with their enemies like Greeks against Persians. As time passed the fascination for the future remained unchanged and is nowadays, thanks to the evolution of technology, more accurate. Our present is constantly changing with the arrival of cell phones, internet and other technologies. As a matter of fact our ambition of knowing the future has increased to become a necessity for everyone and every organization. Born in the late 60's with the discovery of computers, forecasting appears like the response to everybody issues. According to Russel & Taylor - Operations Management (sixth edition) is "the art and science of predicting future events?. Different methods have been found to match the different demands of companies, customers or other organizations.
