A system is disclosed for managing service interactions in a combined service. The system includes a first aspect of service delivery for providing a first service, a second aspect of service delivery for providing a second service, a combined aspect of service delivery for providing a combined service capable of associating the first service to one of the second service. The combined service is implemented using a combined state model, which includes a predetermined number of combined states formed on the basis of the states of the first and the second service and armed detection points for detecting predetermined transitions between the combined states. The combined aspect of service delivery further includes a combined state manager adapted to transmit a control signal to the first and/or the second aspects of service delivery for inducing a predetermined state transition in the respective first and/or the second service in response to the activation of an armed detection point.