Disclosed aspects relate to window management in a stream computing environment to process a stream of tuples using a window of the stream computing environment. A set of tuples which corresponds to the window of the stream computing environment may be detected. The set of tuples may have a set of data. A confidence factor related to a set of expected result data for the set of tuples may be determined based on the set of data of the set of tuples. The set of tuples may correspond to the window of the stream computing environment. The window may be configured in the stream computing environment based on the confidence factor. The window may be configured in the stream computing environment to process the stream of tuples.