Various embodiments of the present invention are provided to adjust a product demand forecast. In one embodiment, a value is determined 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 expresses a probability that a forecast will exceed a demand for a given product. A ratio is determined of the aggregation of the product level demand forecasts to a global demand forecast for the product group in the computer system. The ratio is verified as to whether it is congruous with a historical ratio of past aggregate product level demand forecasts to actual product demand.