This performance work statement seeks contractor-provided environmental modeling and simulation support for AFTAC on a task-order basis, including technical, programmatic, acquisition, expert panel, analytical, engineering, logistical, and consultation services. The contractor must hold a Top-Secret Facility Clearance with Secret Safeguarding capability and be able to provide TS/SCI personnel for the Section 2 scope at time of award. The work supports both operations and maintenance (O&M) and research and development (R&D) tasks for the EMS Program. Support staff must be fully trained, professional, and customer-oriented to deliver responsive, flexible, innovative, and cost-effective services. The majority, if not all, of the work will be performed at the contractor site.