For many event-driven systems, the completeness and consistency (C&C) are the most important characteristics of those software requirements. This paper presents a systematic approach to perform C&C analysis on the requirements, and an intelligent approach to correcting the inconsistencies identified. A formal scenario model isused to represent requirements such that scenario elements of condition guards, events and actions can be extracted automatically. Condition guards associated with a same event are constructed into a tree on which to perform completeness analysis and supplement missing specification. Consistency analysis focuses on three types of inconsistencies and is performed according to the intra-relations among condition guards and inter-relations with actions. An algorithm of inconsistent correction is proposed to guide eliminating the inconsistency identified interactively. Finally, we provide an example of car-alarm system to illustrate the proposed process and techniques.