Abstract: Role Transferability is a basic requirement for emergency management systems. Role specification, relationship expression, and transfer regulations are critical elements of this requirement. This paper discusses the role transferability requirement for emergency management systems; emphasizes that role specification is an underlying mechanism for role transfer; proposes a revised E-CARGO (Environment-Class, Agent, Role, Group, Object) model for role transfer in a group; and presents an algorithm to validate role transfer while maintaining group viability.