Background & Objectives : The sound planning is needed for effective implementation of an emergency exercise. The exercise planning is manifested in the scenario development process. Despite the frequent execution of exercises in the industries and the public domain, there is no uniform pattern for designing scenarios. The present paper aims at devising a new pattern based on the project management body of knowledge ( PMBOK) approach.

 Methods: Ten principles of the PMBOK and their substructures were analyzed. The application processes were extracted in two parts the structural and executive parts. Then, these processes were translated into the its equivalent norms in the emerging scenario development process. Finally, a pattern was proposed for preparing an emergency scenario.

 Result: The proposed method was developed in a ten step process. Step by step implementation of these processes can help one to make an acceptable scenario. In comparison with the two most common international patterns for developing a scenario, the present method has some unique characteristics. Quality, Time, Cost and Interested Parties management are the mentioned properties. In general, the present method has some components that represent more details for users..

 Conclusions : Using the project management body of knowledge approach one can develop a standard frame for developing an emergency scenario.