To ensure operational effectiveness, a comprehensive technical effort must be made to integrate human factors qualitative and quantitative information into system design, testing and acquisition. Such information includes:
- human characteristics
- operator/maintainer capability requirements
- soldier performance data
- system interface requirements
- biomedical factors
- safety factors
- training factors
- manning implication
Goals of Human Factors Engineering
- Make equipment easier to operate, maintain and support
- Reduce the time to accomplish a task
- Reduce the chance for operator error and accident
- Reduce the amount of operator training
- Reduce need for selection of operators with special background or capabilities
- Note 1: Make sure human factors engineering topics are addressed in the:
- Mission Needs Statement
- Operational Requirements Document
- Contract Statement of Work
- Testing and Evaluation plans
- Note 2: The soldier cannot always adapt to design inadequacies. Has a user or user’s representative been an active participant in concept development, system design and test planning?
- Note 3: Equipment performance requirements cannot be considered independent of human performance requirements and capabilities. The total system design includes hardware/software and leaders/users, operators, maintainers and support personnel.
Organization Design (see Key Document 1)
- Obtain essential information
- Mission statements for organization in which the weapon system/equipment is used
- Mission statements for parent organization and subordinate organizations
- Lists of Battlefield Functions (Key Documents 2 and 3) that must be performed to execute the missions
- Required Capabilities
- Organizational wiring diagrams (chains of command)
- Job and job task descriptions
- Develop Preliminary Analysis (or Check) of Total System Functions for Achieving Required Capabilities (see Key Document 4)
- Check for:
- Consistency of missions and Battlefield Functions
- Completeness of Total System functions specifications and Battlefield Functions
- Consistency of responsibilities and authorities
- Appropriateness of span of control
- Adequacy of lines of communication
- Issues in formation and maintenance of trust/cohesion within the organization (see Key Document 5)
- Adequacy of provision for supplies (internal and external support)
- Allocate Total System Functions to Man or Machine (see Key Document 4):
- Human operators
- Equipment
- Human Maintainers
- Embedded fault detection and diagnostics
Job-task performance data
- Obtain data from:
- Checklists
- Interviews
- Questionnaires
- SME observations and ratings
- Direct performance measures
- Video (time & motion studies)
- Number of tasks attempted and completed
- Time to perform
- Accuracy
- Number or proportion of successfully completed tasks
- Human reliability: Consider sources of human error:
- Inadequate aptitude: too difficult for selected personnel (e.g., too many steps)
- Inadequate training
- Equipment configuration induces error
- Environmental conditions induce human error
- Eliminate through design typical sources of human error
Reasons tasks were not completed
- Insufficient manpower
- Inadequate aptitudes
- Poor training
- Poor human factors design
- Lack of, or poor job performance aids
- Lack of feedback devices
Task description & analysis
- Task criticality, frequency of task, learning difficulty, decay rate
- "High driver" tasks
- Information flow analysis
- Task allocation analysis
- Soldier
- Soldier and machine
- Machine
- Manual override of specific functions considered?
- Sequence of operational instructions
- Task-interdependence of crew members
- Workload analysis
- Mental workload:
- Information processing demands
- Memory requirements
- Learning and retention requirements
- Sensory discrimination requirements
- Physical Workload demands:
- Task overload
- Biomedical considerations
- Strength and endurance considerations
- How will degraded manning affect performance?
- Is the number of soldiers planned to perform various critical tasks required by the system sufficient to meet the system performance requirements?
- Psychomotor requirements
- Task environment
- Maintenance, ease of: does system require major dismantling for access to frequently replaced components? Are built-in self-diagnostics feasible?
Equipment and Workspace Design
- Crew interfaces
- Human-computer interface
- Interface compatibility with the capabilities/characteristics of the target audience
- Usability (as judged by the test players via questionnaires, or exhibited in behaviors). Poor interface design or poor training could be reflected by:
- Repetition of task steps
- Increase in error rates
- Excessive use of on-line help or system documentation
- Requests for assistance
- Verbal/non-verbal complaints
- Ergonomic considerations
- Anthropometric data
Stress
- Heat stress
- Psychological stress
- Continuous operations
- Fatigue
- Isolation
- Crowding
- Will battle stress degrade performance?
- NBC conditions: Can the operator perform all required tasks in the prescribed manner while wearing MOPP or other special equipment?