A server of a communication network provides a service to a plurality of users. In the server, a service logic execution environment is stored. The service logic execution environment includes an event router and a service application, which service application includes at least a first component and a second component. The first component is provided with an event handler and the second component is provided with an action handler. The service logic execution environment further includes a flow descriptor which includes a relation between the event handler and the action handler. The event router is adapted to receive an event from the first component and to forward such an event to the second component according to the relation.