HSI Domains



HSI Elements

Manpower is the consideration of the net effect of systems on overall human resource requirements and authorizations (spaces) to ensure that each system is affordable from the standpoint of manpower. It includes analysis of the number of people (military, civilian and contractor) needed to operate, maintain, repair, and support each system being acquired.


The consideration of human aptitudes (i.e., cognitive, physical, and sensory capabilities), knowledge, skills, abilities, and experience levels that are needed to properly perform job tasks across the military, civilian and contractor work force to operate, maintain, and support a system in peacetime and war. Personnel factors are used to develop the DoD Component personnel system classifications and civilian job series of system operators, maintainers, trainers, and support personnel. These "faces" fill the authorized "spaces."


Training is the learning process by which personnel individually or collectively acquire or enhance predetermined job-relevant knowledge, skills, and abilities by developing their cognitive, physical, sensory, and team-dynamic abilities. Training, as a related HSI domain, is the use of analyses, methods and tools to ensure systems training requirements are fully addressed and documented by systems designers and developers to achieve a level of individual and team proficiency that is required to successfully accomplish tasks and missions. Training systems must ensure that the training objectives are met through the delivery of instructional methods, media, personnel, and system support through the life cycle.

Human Factors

Human Factors Engineering is the technical consideration and application of the integration of design criteria, psychological principles, human behavior, capabilities and limitations as they relate to the design, development, test, and evaluation of systems. The goal is to maximize the ability of users to perform at required levels through the elimination of design-induced errors, and to ensure that system operation, maintenance, and support are compatible with the total capabilities and limitations of users operating or maintaining those systems.


Considers environmental considerations (such as water, air, land, space, cyberspace, markets, organizations and the relationships which exist among them and with all living things and systems) that can affect the concept of operations and requirements, particularly human performance, to protect systems from the environment and to protect the environment from system design, manufacturing, operations, sustainment, and disposal activities.

Safety and Occupational Health

Safety is the development of system design characteristics and procedures to minimize the risk of accidents, and mishaps that cause death or injury to operators, maintainers, or support personnel; threatens the operation of the system; or causes cascading failures in other systems. Safety analyses and lessons learned are used to aid in development of design features that prevent safety hazards to the greatest extent possible and manage safety hazards that cannot be avoided. 

Occupational health focuses on system design features and procedures that serve to minimize the risk of injury, acute or chronic illness, disability, and enhance job performance of personnel who operate, maintain, or support the system. Occupational health analyses and lessons learned are used to aid in development of design features that prevent health hazards where possible, and provide recommendations on personal protective equipment, protective enclosures, or mitigation measures where health hazards cannot be avoided.


The consideration of the characteristics of a system (e.g., life support, body armor, helmets, plating, egress/ejection equipment, air bags, seat belts, electronic shielding, etc.) that reduce susceptibility of the total system to mission degradation or termination. The goal is to reduce detectability of the warfighter, prevent attack if detected, prevent damage if attacked, minimize medical injury if wounded or otherwise injured, and reduce physical and mental fatigue. These issues must be considered in the context of the full spectrum of anticipated operations and operational environments and for all personnel who will interact with the system (e.g., users/customers, operators, maintainers, or other support personnel). Adequate protection and escape systems must provide for personnel and total system survivability when they are threatened with harm.


Habitability is the consideration of the characteristics of systems focused on satisfying personnel needs that are dependent upon physical environment. Habitability analyzes factors of working conditions and accommodations that are necessary to sustain the morale, safety, health, and comfort of the user population that contribute directly to personnel effectiveness and mission accomplishment.