U.S. Air Force Fact Sheet 711TH HUMAN PERFORMANCE INTEGRATION DIRECTORATE: WHAT IS HSI? Human Systems Integration (HSI) is a process to ensure systems are designed and developed that effectively and affordably integrate with human capabilities and limitations. The HSI process considers : human factors engineering manpower, personnel training environmental, safety, and occupational health (ESOH) survivability habitability These domains must be taken into account throughout system design, development, fielding, and sustainment.