Integrating simulations for training, mission rehearsal, test and evaluation, and analytical purposes is necessary but risky. No single simulation provides the comprehensive, sufficiently-accurate, synthetic environment required. The integration risk lies in the different assumptions and constraints made when the individual simulations were designed and developed. For example, some simulations include water features as an obstacle. Others assume perfect command and control. Lack of awareness of these differences and a means to reconcile these assumptions / constraints impacts the efficacy of the resulting integrated simulation.

Rapidly and accurately determining whether a set of simulations can be integrated to produce a working, federated simulation producing valid results remains one of the key challenges for distributed simulation. This joint effort between the Simulation Interoperability Standards Organization (SISO) Federation Engineering Agreements Template (FEAT) Product Support Group (PSG), Distributed Simulation Engineering and Execution Process (DSEEP) PSG, and Verification, Validation and Accreditation (VV&A) Product Development Group (PDG) is a step toward producing a systems engineering artifact-based approach to addressing that challenge. The methodology is called Simulation Interoperability Readiness Levels (SIRL).