INRAT-H key terms

An error in which a correctly planned action is carried out incorrectly, usually during a familiar routine, such as pressing the wrong adjacent button or transposing digits.

An error of omission in which a planned action is forgotten or an intended step is skipped, typically during routine or highly practiced tasks with low attention demand.

An error arising from a correct execution of a wrong intention, where the plan itself is inadequate because of faulty rules, misdiagnosis, or incomplete knowledge.

A deviation in highly practiced, largely automatic performance, appearing as slips of action or lapses of memory rather than as faulty reasoning or planning.

A failure in which a known if-then rule is misapplied or a good rule is applied to a situation it does not fit, often through misdiagnosis of the condition.

An error occurring when a person faces an unfamiliar situation with no applicable procedure and must reason from first principles, making misdiagnosis and mental overload likely.

A deliberate departure from a rule, procedure, or standard that the person knows exists, often driven by perceived efficiency, workload pressure, or a belief that the rule is unnecessary.

The sequence of events and conditions along which small deviations accumulate and combine until a significant failure becomes possible or inevitable.

A dormant weakness in design, maintenance, training, or organization that lies hidden until local triggering events expose it and combine with active failures.

The arrangement of multiple independent barriers, such as engineered safeguards, procedures, and human checks, so that no single failure can produce serious consequences.

A person's ongoing understanding of what is happening around them, built from perceiving relevant cues, interpreting their meaning, and projecting how conditions will develop.

The process of distributing limited attentional resources across tasks, displays, and alarms, which can fail through tunneling, distraction, or over-focus on a single signal.

A narrowing of attention onto one task or alarm while other relevant information is neglected, commonly occurring under high stress, time pressure, or surprise.

A limited-capacity store used to hold and manipulate information briefly during reasoning, calculation, and procedure following, easily disrupted by interruption or overload.

An internal representation of how a system works and how it will respond to actions, which guides expectations, diagnosis, and interpretation of unexpected indications.

The tendency to seek, notice, and favor information that supports an existing belief while discounting evidence that contradicts it, delaying recognition of an evolving fault.

Persistent adherence to an initial diagnosis or course of action despite accumulating contrary evidence, causing a delay in considering alternative explanations.

A model of expert decision making in which a familiar situation is recognized from experience and the first workable option is evaluated mentally rather than compared against alternatives.

The study of how experienced people make decisions in real settings characterized by time pressure, uncertainty, incomplete information, and high stakes.

The total mental demand imposed by a task, including the amount of information to hold, process, and act on within a given time.

A rapid burst of many alarms in a short period that exceeds the operator's capacity to interpret and respond, obscuring the most important signals.

A systematic process of reviewing, prioritizing, and reducing alarms so that each one is necessary, correctly set, and clearly tied to an operator action.

The displays, controls, alarms, and interaction methods through which operators monitor and act on a plant or process.

The deliberate assignment of tasks between humans and automated systems, ideally matching human strengths in judgment with machine strengths in speed and consistency.

Reduced monitoring and vigilance when an automated system is trusted to handle a task, leading to slower detection when the automation fails or behaves unexpectedly.

The degree to which personnel follow written procedures as intended, influenced by procedure usability, training, supervision, and perceived relevance to the situation.

Confirmation that a procedure is technically correct and can be carried out by real operators in the actual control room under realistic conditions.

A structured breakdown of a job into its goals, steps, information needs, and decisions, used to identify error potential and design support.

A review method in which analysts step through a task from the user's viewpoint, asking whether each action is evident, visible, and properly supported by the interface.

The roughly 24-hour internal cycle regulating sleep, alertness, body temperature, and hormone release, which adapts slowly to shift changes and night work.

A state of reduced mental or physical capability resulting from prolonged effort, insufficient sleep, or extended wakefulness, degrading vigilance and reaction time.

A temporary period of impaired alertness and slower performance immediately after waking, especially after abrupt awakening from deep sleep or during the biological night.

The relationship between the demands a task places on a person and the resources available to meet them, ranging from underload to overload.

A psychological and physiological response to demands perceived as exceeding available resources, which can narrow attention and impair judgment.

Training and practices that develop non-technical skills such as communication, leadership, teamwork, and workload management to improve safety in high-consequence operations.

A message exchange in which the receiver repeats back the instruction and the sender confirms it, ensuring that intent and understanding match.

The willingness and skill to state concerns clearly and persistently, especially when a team member perceives a risk that others may not have recognized.

A short structured exchange before a task or shift that aligns the team on goals, roles, expected conditions, and known risks.

The transfer of responsibility and operational information between outgoing and incoming personnel, requiring accurate, prioritized, and verified communication.

The shared values, beliefs, and behaviors that determine how seriously an organization treats safety, including reporting, learning, and willingness to challenge.

A framework that distinguishes honest error from reckless behavior, encouraging reporting while still holding people accountable for deliberate unsafe acts.

The gradual acceptance of a departure from standards as normal because it has not yet produced harm, eroding margins until a serious event occurs.

The willingness of personnel to voice safety concerns or question a course of action, which depends on psychological safety and perceived leadership support.

A structured method for estimating the likelihood and causes of human errors in a task and identifying where performance-shaping factors increase or reduce risk.

A condition such as fatigue, training, stress, interface quality, or time pressure that influences the probability of successful human performance in a task.

Practice in a realistic mock control room or computer model that builds skill and lets crews rehearse rare, high-consequence scenarios safely.

The systematic process of defining required knowledge and skills, assessing them, and maintaining evidence that personnel remain capable of performing their roles.

A formal assessment that verifies a candidate meets regulatory knowledge and skill standards before being authorized to operate or supervise a facility.

Instruction built around realistic, unfolding situations that require trainees to apply knowledge, make decisions, and communicate under conditions resembling actual work.