Abstract: Aspects of the present invention include improvements to a management decision support system. Before improvement, the system includes a computer system having memory and resources, a retail demand forecasting program applying one or more forecasting approaches, running on the computer system and utilizing the output, said analysis programs generating at least one of (a) order of goods from a supplier-related data, (b) allocation of the goods to be shipped by the supplier-related data, or (c) distribution of goods to selling locations-related data. The improvements, according to one aspect of the invention, include a causal calendar utilized by the forecasting program to generate the output, the calendar including certain attributes for a plurality of events, and an analysis program to generate open to buy reports. Other aspects of the present invention are described in the specification, drawing and claims.