During the last years, scenarios, use-cases and other techniques for modelling the global behaviour have been introduced into object-oriented analysis. However, aggregation and generalisation of scenarios as well as the integration of scenarios reflecting different abstraction levels are usually not supported. By integrating these concepts into an enhanced scenario modelling technique we could overcome some of the drawbacks of current approaches, e.g. their limitation to monolithic systems with fixed automation boundaries, their restriction to flat event structures, and their insufficient support of the transition from analysis to design.