Systems, methods, and computer program products to perform an operation comprising determining, based on actual coverage point data for a first time interval and expected coverage point data, that a first set of lines of source code associated with the actual and expected coverage point data have not been executed by a system, instantiating, in the system, an action code associated with the first set of lines of source code and an effect code associated with the action code, and determining, based on a final state of the effect code, whether the action code executed correctly in the system.