A method and apparatus for processing a real-time data stream. The method for processing a real-time data stream based on a rule includes selecting a rule corresponding to a current factory state with reference to a rule engine in which factory states are mapped to rules corresponding thereto, analyzing a real-time data stream to be used to control a factory resource, and, when a result of the analysis satisfies a condition defined in the rule, controlling a factory resource so as to take an action corresponding to the defined condition. According to the method, the real-time data streams collected in a factory or flowing from outside the factory are processed to be suitable for the environment in the factory, whereby the operating rate and productivity of the factory may be improved.