1. A computer-implemented method comprising: defining a forecast class that represents forecasts of different types, wherein the forecast class identifies a set of relationships of a forecast with a plurality of entities related to the forecast, the different forecast types comprise a demand forecast type and a supply forecast type, and the forecast class includes a designated data element to store data indicating whether data elements of the forecast class store data of a demand forecast; and representing the forecasts provided by the forecast class in a common format.