Requirements specification for distributed intelligent systems using the Cube Tool methodology

The geographical dispersion of distributed intelligent systems requires the consideration of both processes and communications in the formulation of requirements. Cube Tool is a methodology used to derive the processing and communication needs for each system function. An approach is introduced for extending the applicability of Cube Tool to the determination of requirements for distributed intelligent systems. First, using Cube Tool for each function, a Petri net is derived that models all processes and communications for the correct execution of the function. Then, for a given scenario, these nets are interconnected and the steps of the methodology are applied again to derive the Petri net that represents the mission-dependent requirements for the system. The methodology is illustrated through a fictitious air interdiction mission system