1. A system for forecasting demand for a product, comprising: a processor circuit having a processor and a memory; forecasting logic stored in the memory and executable by the processor, the forecasting logic comprising: logic that determines a value of an aggregation of a plurality of product level demand forecasts for a respective plurality of products in a product group at a desired value of a critical ratio, the critical ratio expressing a probability that a forecast will exceed a demand for a given product; logic that determines a forecast ratio of the aggregation of the product level demand forecasts to a global demand forecast for the product group; logic that verifies that the forecast ratio is congruous with a historical ratio of past aggregate product level demand forecasts to actual product demand, where the forecast ratio is congruous with the historical ratio if the forecast ratio falls within a predefined tolerance of the historical ratio; logic that determines an adjusted value of the critical ratio at which a calculation of the aggregation of the plurality of product level demand forecasts results in an adjusted value for the forecast ratio that is congruous with the historical ratio if the forecast ratio is not verified to be congruous with the historical ratio; and logic that provides a product level demand forecast to an inventory control system, where the inventory control system is configured to control a quantity of at least one product in an inventory based upon the product level demand forecast, the product level demand forecast being determined at the desired value of the critical ratio if the forecast ratio is verified to be congruous with the historical ratio, and the product level demand forecast being determined at the adjusted value of the critical ratio if the forecast ratio is not verified to be congruous with the historical ratio.