Abstract: Requirements modeling is a key procedure in Requirements Engineering. "hhis paper put forward a bchaviororiented modeling methods; Ploted out problem domain of target system into several sub-domains. Viewpoints were then created in each sub-domain. Within each Viewpoint, a series of scenarios would be established according to rectuiremenu. A Scenario Behavior Model(SCBM) could then be established to specify each scenario by Behavior Description Language(BDL). A Viewpoint Behavior Model(VBM) could be constructed of all SBM within the Viewpoint and a System Behavior Model(SBM) could be constructed of all VBMs. A set of properties and their verification methods were proposed to check the correctness of behavior model and properties of the target system. Based on the methods above, a Behavior-oriented Requirements Modeling Tool(BRMT) was implemented.

Key words: Requirements modeling, Software behavior, Viewpoint, Scenario, Behavior description language