The program manager employs human factors engineering to design systems that require minimal manpower; provide effective training; can be operated, maintained and supported by users; and are suitable (habitable and safe with minimal environmental and occupational health hazards) and survivable (for both the crew and equipment). In accordance with DoD Instruction 5000.02,

"The PM shall take steps (e.g., contract deliverables and Government/contractor IPT teams) to ensure ergonomics, human factors engineering, and cognitive engineering is employed during systems engineering over the life of the program to provide for effective human-systems interfaces and to meet HSI requirements. Where practicable and cost effective, system designs shall minimize or eliminate system characteristics that require excessive cognitive, physical, or sensory skills; entail extensive training or workload-intensive tasks; result in mission-critical errors; or produce safety or health hazards."

The human factors that need to be considered in the integration are discussed below:

6.3.4.2. Overview

Human factors are the end-user cognitive, physical, sensory, and team dynamic abilities required to perform system operational, maintenance, and support job tasks. Human factors engineers contribute to the acquisition process by ensuring that the program manager provides for the effective utilization of personnel by designing systems that capitalize on and do not exceed the abilities (cognitive, physical, sensory, and team dynamic) of the user population. The human factors engineering community works to integrate the human characteristics of the user population into the system definition, design, development, and evaluation processes to optimize human-machine performance for operation, maintenance, and sustainment of the system.

Human factors engineering is primarily concerned with designing human-system interfaces consistent with the physical, cognitive, and sensory abilities of the user population. Human-system interfaces include:

Functional interfaces (functions and tasks, and allocation of functions to human performance or automation);
Informational interfaces (information and characteristics of information that provide the human with the knowledge, understanding and awareness of what is happening in the tactical environment and in the system);
Environmental interfaces (the natural and artificial environments, environmental controls, and facility design);
Cooperational interfaces (provisions for team performance, cooperation, collaboration, and communication among team members and with other personnel);
Organizational interfaces (job design, management structure, command authority, policies and regulations that impact behavior);
Operational interfaces (aspects of a system that support successful operation of the system such as procedures, documentation, workloads, job aids);
Cognitive interfaces (decision rules, decision support systems, provision for maintaining situational awareness, mental models of the tactical environment, provisions for knowledge generation, cognitive skills and attitudes, memory aids); and,
Physical interfaces (hardware and software elements designed to enable and facilitate effective and safe human performance such as controls, displays, workstations, worksites, accesses, labels and markings, structures, steps and ladders, handholds, maintenance provisions, etc.).

6.3.4.3. Parameters/Requirements

Human factors requirements, objectives, and thresholds should be derived from each of the Human Systems Integration (HSI) domains and should provide for the effective utilization of personnel through the accommodation of the cognitive, physical, and sensory characteristics that directly enhance or constrain system performance. In many cases, the interface design limitation may require tradeoffs in several of the other domains and vice, versa.

Cognitive requirements address the human's capability to evaluate and process information. Requirements are typically stated in terms of response times and are typically established to avoid excessive cognitive workload. Operations that entail a high number of complex tasks in a short time period can result in cognitive overload and safety hazards. The capability documents should specify whether there are human-in-the-loop requirements. This could include requirements for "human in control," "manual override," or "completely autonomous operations." Knowledge, skills and abilities for operators, maintainers and other support personnel continuously change with the increasing complexity of emerging systems. These requirements should be cross correlated with each of the HSI domains.

Physical requirements are typically stated as anthropometric (measurements of the human body), strength, and weight factors. Physical requirements are often tied to human performance, safety, and occupational health concerns. To ensure the users can operate, maintain, and support the system, requirements should be stated in terms of the user population. For instance, when the user requires a weapon that is "one-man portable," weight thresholds and objectives should be based on strength limitations of the user population and other related factors (e.g., the weight of other gear and equipment and the operational environment). For example, it may be appropriate to require that "the system be capable of being physically maintained by central 90% of both the male and female population, inclusive of battle dress, or arctic and Mission Oriented Protective Postures-Level 4 protective garments inside the cab," or that "the crew station physically accommodate 90% of the female/male population, defined by current anthropometric data, for accomplishment of the full range of mission functions."

Sensory requirements are typically stated as visual, olfactory (smell), or hearing factors. The Capability Development Document should identify operational considerations that affect sensory processes. For example, systems may need to operate in noisy environments where weapons are being fired or on an overcast moonless night with no auxiliary illumination. Visual acuity or other sensory requirements may limit the target audience for certain specialties.

6.3.4.4. Application of Human Factors Engineering (HFE)

HFE plays an important role in each phase of the acquisition cycle, to include requirements development, system definition, design, development, evaluation, and system support for reliability and maintainability in the field. To realize the potential of HFE contributions, HFE must be incorporated into the design process at the earliest stages of the acquisition process (i.e., during the Materiel Solution Analysis and Technology Development phases). It should be supported by inputs from the other Human Systems Integration (HSI) domains as well as the other Systems Engineering processes. The right decisions about the human-machine interfaces early in the design process will optimize human and hence, total systems performance. HFE participation continues to each succeeding acquisition phase, continuing to work tradeoffs based on inputs from the other HSI domains and the hardware and software designs / adaptations. The HFE practitioners provide expertise that includes design criteria, analysis and modeling tools, and measurement methods that will help the program office design systems that are operationally suitable, safe, survivable, effective, usable, and cost-effective. In any system acquisition process, it is important to recognize the differences between the competencies (skills and knowledge) required for the various warfighters. Application of HFE processes will lead to an understanding of the competencies needed for the job, and help identify if requirements for knowledge, skills, and abilities (KSAs) exceed what the user can provide and whether the deficiency will lead to a training or operational problem. HFE tools and techniques can be used to identify the KSAs of the target audience and account for different classes and levels of users and the need for various types of information products, training, training systems and other aids. While it is critical to understand the information processing and net-centric requirements of the system, it is equally important to understand the factors affecting format and display of the data presented to the user to avoid cognitive overload. This applies equally to the system being designed as well as to the systems which will interface with the system. The system should not place undue workload or other stress on systems with which it must interface.

6.3.4.5. General Guidelines

Human Factors Engineering (HFE) principles, guidelines, and criteria should be applied during development and acquisition of military systems, equipment, and facilities to integrate personnel effectively into the design of the system. An HFE effort should be provided to: (a) develop or improve all human interfaces of the system; (b) achieve required effectiveness of human performance during system operation, maintenance, support, control, and transport; and (c) make economical demands upon personnel resources, skills, training, and costs. The HFE effort should be well integrated with the other Human Systems Integration domain participation, and should include, but not necessarily be limited to, active participation in the following three major interrelated areas of system development.

6.3.4.5.1. Analysis

Identify the functions that must be performed by the system in achieving its mission objectives and analyze them to determine the best allocation to personnel, equipment, software, or combinations thereof. Allocated functions should be further dissected to define the specific tasks that must be performed to accomplish the functions. Each task should be analyzed to determine the human performance parameters; the system, equipment, and software capabilities; and the operational / environmental conditions under which the tasks will be conducted. Task parameters should be quantified where possible, and should be expressed in a form that permits effectiveness studies of the human-system interfaces in relation to the total system operation. Human Factors Engineering high-risk areas should be identified as part of the analysis. Task analysis should include maintenance and sustainment functions performed by crew and support facilities. Analyses should be updated as required to remain current with the design effort.

6.3.4.5.2. Design and Development

Human Factors Engineering (HFE) should be applied to the design and development of the system equipment, software, procedures, work environments, and facilities associated with all functions requiring personnel interaction. This HFE effort should convert the mission, system, and task analysis data into a detailed design and development plan to create a human-system interfaces that will operate within human performance capabilities, facilitate / optimize human performance in meeting system functional requirements, and accomplish the mission objectives.

6.3.4.5.3. Test and Evaluation (T&E)

Human Factors Engineering (HFE) and the evaluation of all human interfaces should be integrated into engineering design and development tests, contractor demonstrations, flight tests, acceptance tests, other development tests and operational testing. Compliance with human interface requirements should be tested as early as possible. T&E should include evaluation of maintenance and sustainment activities and evaluation of the dimensions and configuration of the environment relative to criteria for HFE and each of the other Human Systems Integration domains. Findings, analyses, evaluations, design reviews, modeling, simulations, demonstrations, and other early engineering tests should be used in planning and conducting later tests. Test planning should be directed toward verifying that the system can be operated, maintained, supported, and controlled by user personnel in its intended operational environment with the intended training. Test planning should also consider data needed or provided by operational test and evaluation. (See section 9.5.2).

6.3.4.6. Life-Cycle Sustainment Plan

The program manager should summarize the steps planned to be taken (e.g., government and contract deliverables) to ensure human factors engineering (HFE) is employed during systems engineering over the life of the program to provide for effective human-system interfaces and meet HFE and other Human Systems Integration requirements.

6.3.5. Environment, Safety and Occupational Health (ESOH)

6.3.5.1. Environment, Safety and Occupational Health (ESOH) Overview

Each of the various military departments / services treat the three Human Systems Integration (HSI) domains of Environment, Safety, and Occupational Health differently, based on oversight and reporting responsibility within each of the services. DoD ESOH Guidance for systems acquisition programs can be found in Chapter 4, Systems Engineering, section 4.3.18.9, and in the ESOH Special Interest Area on the Acquisition Community Connection. What is important to the HSI practitioner and the systems engineer is that these three domains are of vital importance to the HSI effort and must be integrated within the HSI effort. While the ESOH communities have unique reporting requirements that trace to National level mandates, the importance of integrating these domains in the HSI construct cannot be overemphasized. The human aspect brings a host of issues to a system that must be accommodated in each of these three areas and they must each be considered in consonance with the other HSI domains. How they are considered in an integrated manner is left to the Program Manager and Systems Engineering.

Environment includes the natural and manmade conditions in and around the system and the operational context within which the system will be operated and supported. This "environment" affects the human's ability to function as a part of the system.

Safety factors consist of those system design characteristics that serve to minimize the potential for mishaps causing death or injury to operators, maintainers and supporters or threaten the survival and/or operation of the system. Prevalent issues include factors that threaten the safe operation and/or survival of the platform; walking and working surfaces including work at heights; pressure extremes; and control of hazardous energy releases such as mechanical, electrical, fluids under pressure, ionizing or non-ionizing radiation (often referred to as "lock-out/tag-out"), fire, and explosions.

Occupational health factors are those system design features that serve to minimize the risk of injury, acute or chronic illness, or disability; and/or reduce job performance of personnel who operate, maintain, or support the system. Prevalent issues include noise, chemical safety, atmospheric hazards (including those associated with confined space entry and oxygen deficiency), vibration, ionizing and non-ionizing radiation, and human factors issues that can create chronic disease and discomfort such as repetitive motion diseases. Many occupational health problems, particularly noise and chemical management, overlap with environmental impacts. Human factors stresses that create risk of chronic disease and discomfort overlap with occupational health considerations.

6.3.5.2. Environment, Safety and Occupational Health (ESOH) Hazard Parameters/Requirements

Environment, safety and health hazard parameters should address all activities inherent to the life cycle of the system, including test activity, operations, support, maintenance, and final demilitarization and disposal. Environment, safety and health hazard requirements should be stated in measurable terms, whenever possible. For example, it may be appropriate to establish thresholds for the maximum level of acoustic noise, vibration, acceleration shock, blast, temperature or humidity, or impact forces etc., or "safeguards against uncontrolled variability beyond specified safe limits," where the Capability Documents specify the "safe limits." Safety and health hazard requirements often stem from human factor issues and are typically based on lessons learned from comparable or predecessor systems. For example, both physical dimensions and weight are critical safety requirements for the accommodation of pilots in ejection seat designs. Environment, safety and health hazard thresholds are often justified in terms of human performance requirements, because, for example, extreme temperature and humidity can degrade job performance and lead to frequent or critical errors. Another methodology for specifying safety and health requirements is to specify the allowable level of residual risk as defined in MIL-STD-882D, "DoD Standard Practice for System Safety," for example, "There shall be no high or serious residual risks present in the system."

6.3.5.3. Environment, Safety and Occupational Health (ESOH) Planning

6.3.5.3.1. Programmatic Environment, Safety, and Occupational Health (ESOH) Evaluation (PESHE)

The Human Systems Integration Plan should recognize the appropriate timing for the PESHE and define how the program intends to ensure the effective and efficient flow of information to and from the ESOH domain experts to work the integration of environment, safety and health considerations into the systems engineering process and all its required products.

6.3.5.3.2. Health Hazard Analysis (HHA)

Health Hazards Analysis(HHA) should be conducted during each phase of the acquisition process beginning with a review of issues related to predecessor systems. During early stages of the acquisition process, sufficient information may not always be available to develop a complete HHA. As additional information becomes available, the initial analyses are refined and updated to identify health hazards, assess the risks, and determine how to mitigate the risks, formally accept the residual risks, and monitor the effectiveness of the mitigation measures. The health hazard risk information is documented in the PESHE. Health hazard assessments should include cost avoidance figures to support trade-off analysis. There are nine health hazard issues typically addressed in a health hazard analysis (HHA):

Acoustical Energy. The potential energy that transmits through the air and interacts with the body to cause hearing loss or damage to internal organs.
Biological Substances. An infectious substance generally capable of causing permanent disability or or life-threatening or fatal disease in otherwise healthy humans.
Chemical Substances. The hazards from excessive airborne concentrations of toxic materials contracted through inhalation, ingestion, and skin or eye contract.
Oxygen Deficiency. The displacement of atmospheric oxygen from enclosed spaces or at high altitudes.
Radiation Energy. Ionizing: The radiation causing ionization when interfacing with living or inanimate mater. Non-ionizing: The emissions from the electromagnetic spectrum with insufficient energy to produce ionizing of molecules.
Shock. The mechanical impulse or impact on an individual from the acceleration or deceleration of a medium.
Temperature Extremes and Humidity. The human health effects associated with high or low temperatures, sometimes exacerbated by the use of a materiel system.
Trauma. Physical: The impact to the eyes or body surface by a sharp or blunt object. Musculoskeletal: The effects to the system while lifting heavy objects.
Vibration. The contact of a mechanically oscillating surface with the human body.

6.3.6. Survivability

6.3.6.1. Survivability Overview

Survivability factors consist of those system design features that reduce the risk of fratricide, detection, and the probability of being attacked; and that enable the crew to withstand natural and man-made hostile environments without aborting the mission or suffering acute chronic illness, disability, or death. Survivability attributes, as described in the Joint Military Dictionary (JP 1-02), are those that contribute to the survivability of manned systems. In the HSI construct, the human is considered integral to the system and personnel survivability should be considered in the encompassing "system" context.

6.3.6.2. Survivability Parameters/Requirements

A Survivability / Force Protection Key Performance Parameter should be considered for any "manned system or system designed to enhance personnel survivability" when the system may be employed in an asymmetric threat environment. The Capability Documents should include applicable survivability parameters. This may include requirements to eliminate significant risks of fratricide or detectability, or to be survivable in adverse weather conditions and the nuclear, biological, and chemical (NBC) battlefield. NBC survivability, by definition, includes the instantaneous, cumulative, and residual effects of NBC weapons upon the system, including its personnel. It may be appropriate to require that the system "permit performance of mission-essential operations, communications, maintenance, re-supply and decontamination tasks by suitably clothed, trained, and acclimatized personnel for the survival periods and NBC environments required by the system."

The consideration of survivability should also include system requirements to ensure the integrity of the crew compartment and rapid egress when the system is damaged or destroyed. It may be appropriate to require that the system provide for adequate emergency systems for contingency management, escape, survival, and rescue.

6.3.6.3. Survivability Planning

The Joint Capabilities Integration and Development System capability documents define the program's combat performance and survivability needs. Consistent with those needs, the program manager should establish a survivability program. This program, overseen by the program manager, should seek to minimize (1) the probability of encountering combat threats, (2) the severity of potential wounds and injury incurred by personnel operating or maintaining the system, and (3) the risk of potential fratricidal incidents. To maximize effectiveness, the program manager should assess survivability in close coordination with systems engineering and test and evaluation activities.

Survivability assessments assume the warfighter is integral to the system during combat. Damage to the equipment by enemy action, fratricide, or an improperly functioning component of the system can endanger the warfighter. The survivability program should assess these events and their consequences. Once these initial determinations are made, the design of the equipment should be evaluated to determine if there are potential secondary effects on the personnel. Each management decision to accept a potential risk should be formally documented by the appropriate management level as defined in DoD Instruction 5000.02.

During early stages of the acquisition process, sufficient information may not always be available to develop a complete list of survivability issues. An initial report is prepared listing those identified issues and any findings and conclusions. Classified data and findings are to be appropriately handled according to each DoD Component's guidelines. Survivability issues typically are divided into the following components:

Reduce Fratricide. Fratricide is the unforeseen and unintentional death or injury of "friendly" personnel resulting from friendly forces employment of weapons and munitions. To avoid these types of survivability issues, personnel systems and weapon systems should include anti-fratricide systems, such as Identification of Friend or Foe and Situational Awareness systems.
Reduce Detectability. Reduce detectability considers a number of issues to minimize signatures and reduce the ranges of detection of friendly personnel and equipment by confounding visual, acoustic, electromagnetic, infrared/thermal, and radar signatures and methods that may be utilized by enemy equipment and personnel. Methods of reducing detectability could include camouflage, low-observable technology, smoke, countermeasures, signature distortion, training, and/or doctrine.
Reduce Probability of Attack. Analysts should seek to reduce the probability of attack by avoiding appearing as a high value-target and by actively preventing or deterring attack by warning sensors and use of active countermeasures.
Minimize Damage if Attacked. Analysts should seek to minimize damage, if attacked, by: 1) designing the system to protect the operators and crewmembers from enemy attacks; 2) improving tactics in the field so survivability is increased; 3) designing the system to protect the crew from on-board hazards in the event of an attack (e.g., fuel, munitions, etc.); and, 4) designing the system to minimize the risk to supporting personnel if the system is attacked. Subject matter experts in areas such as nuclear, biological and chemical warfare, ballistics, electronic warfare, directed energy, laser hardening, medical treatment, physiology, human factors, and Information Operations can add additional issues.
Minimize Injury. Analysts should seek to minimize: 1) combat, enemy weapon-caused injuries; 2) the combat-damaged system's potential sources and types of injury to both its crew and supported troops as it is used and maintained in the field; 3) the system's ability to prevent further injury to the fighter after being attacked; and 4) the system's ability to support treatment and evacuation of injured personnel. Combat-caused injuries or other possible injuries are addressed in this portion of personnel survivability, along with the different perspectives on potential mechanisms for reducing damage. Evacuation capability and personal equipment needs (e.g. uniform straps to pull a crew member through a small evacuation port are addressed here.
Minimize Physical and Mental Fatigue. Analysts should seek to minimize injuries that can be directly traced to physical or mental fatigue. These types of injuries can be traced to complex or repetitive tasks, physically taxing operations, sleep deprivation, or high stress environments.
Survive Extreme Environments. This component addresses issues that will arise once the warfighter evacuates or is forced from a combat-affected system such as an aircraft or watercraft and must immediately survive extreme conditions encountered in the sea or air until rescued or an improved situation on land is reached. Dependent upon requirements, this may also include some extreme environmental conditions found on land, but generally this component is for sea and air where the need is immediate for special consideration to maintain an individual's life. Survival issues for downed pilots behind enemy lines should be considered here.

The program manager should summarize plans for survivability in the Life-Cycle Sustainment Plan and address survivability risks and plans for risk mitigation. If the system or program has been designated by Director, Operational Test & Evaluation, for live fire test and evaluation (LFT&E) oversight, the program manager should integrate T&E to address crew survivability issues into the LFT&E program to support the Secretary of Defense LFT&E Report to Congress (10 USC 2366). The program manager should address special equipment or gear needed to sustain crew operations in the operational environment.

6.3.7. Habitability

6.3.7.1. Habitability Overview

Habitability factors are those living and working conditions that are necessary to sustain the morale, safety, health, and comfort of the user population. They directly contribute to personnel effectiveness and mission accomplishment, and often preclude recruitment and retention problems. Examples include: lighting, space, ventilation, and sanitation; noise and temperature control (i.e., heating and air conditioning); religious, medical, and food services availability; and berthing, bathing, and personal hygiene.

Habitability consists of those characteristics of systems, facilities (temporary and permanent), and services necessary to satisfy personnel needs. Habitability factors are those living and working conditions that result in levels of personnel morale, safety, health, and comfort adequate to sustain maximum personnel effectiveness, support mission performance, and avoid personnel retention problems.

6.3.7.2. Habitability Parameters/Requirements

Habitability is one of several important factors included in the overall consideration of unit mission readiness. Per DoD Instruction 5000.02, the program manager shall work with habitability representatives to establish requirements for the physical environment (e.g., adequate light, space, ventilation, and sanitation, and temperature and noise control) and, if appropriate, requirements for personal services (e.g., religious, medical, and mess) and living conditions (e.g., berthing and personal hygiene) if the habitability factors have a direct impact on meeting or sustaining performance requirements, sustaining mission effectiveness, or that have such an adverse impact on quality of life or morale that recruitment or retention rates could be degraded. Examples include requirements for heating and air-conditioning, noise filters, lavatories, showers, dry-cleaning and laundry.

While a system, facility, and/or service should not be designed solely around optimum habitability factors, habitability factors cannot be systematically traded-off in support of other readiness elements without eventually degrading mission performance.

6.3.7.3. Habitability Planning

The program manager should address habitability planning in the Life-Cycle Sustainment Plan and identify habitability issues that could impact personnel morale, safety health, or comfort or degrade personnel performance, unit readiness, or result in recruitment or retention problems.

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