This is a "Computer system designed to provide assistance in determining and evaluating alternative courses of action. A DSS (1) acquires data from the mass of routine transactions of a firm, (2) analyzes it with advanced statistical techniques to extract meaningful information, and (3) narrows down the range of choices by applying rules based on decision theory. Its objective is facilitation of 'what if' analysis and not replacement of a manager's judgment." (from BusinessDictionary.com)