Abstract: Event model of software systems can model system behaviors effectively.However,since the system structure should be known and the spatial-temporal attributes of events should be considered due to the hybrid and distributed properties of cyber-physical systems (CPS),new challenges arise when building CPS’s event model.From the angle of requirements analysis,this paper proposed a goal oriented approach to deal with the challenges.This approach defines the users’goal on CPS as the causal relationships between events,that is a goal expresses the relationship that the occurrence of an event will cause of another event.Then,it analyzes and develops the event model based on users’ requirements on CPS by means of “And/Or” decomposition.An adaptive cruise control system has been used to illustrate the proposed approach.

Key words: Cyber-physical systems,Requirements analysis,Goal oriented approach,Event model