Basic Qualifications for Principal Modeling & Simulation Systems Engineer: BS degree in Mechanical, Electrical Engineering, Physics, or a STEM field with 5+ years of related experience, MS degree in STEM field with 3+ years of related experience, or PhD in STEM field with 1+ years of related experience. Principal Modeling & Simulation Systems Engineer: BS degree in Mechanical, Electrical Engineering, Physics, or a STEM field with 8+ years of related experience, MS degree in STEM field with 6+ years of related experience, or PhD in STEM field with 4+ years of related experience.