ASP Fellowship II flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Residual risk

The risk remaining after all planned protective measures have been implemented. It must be documented, evaluated against acceptance criteria, and formally accepted by an authorized person.

ALARP principle

Risk should be reduced as low as reasonably practicable. Further reduction is required unless its cost is grossly disproportionate to the safety benefit obtained.

Fault tree AND gate

For independent inputs, the AND gate output probability equals the product of the input probabilities. Output occurs only when all inputs occur, so redundancy lowers the top-event probability.

Bow-tie analysis

A diagram linking threats through preventive barriers to a top event, then through mitigative barriers to consequences. It shows barrier dependence and degradation clearly.

System safety program plan

A document defining safety scope, organization, responsibilities, required tasks, milestones, deliverables, and risk acceptance authority for a specific program or project.

Hazard tracking log

A controlled record of each hazard's description, causal factors, severity and likelihood, mitigation, owner, status, residual risk, acceptance signature, and closure evidence.

Risk acceptance authority

The designated role empowered to accept a specified residual risk level. Higher-severity risks require acceptance at more senior organizational levels than low-severity risks.

Tailoring safety tasks

Selecting which standard safety tasks apply to a program. Omitted tasks require documented justification and approval, not silent exclusion from the plan.

HAZOP guide words

Standard prompts (no, more, less, as well as, part of, reverse, other than) applied to process parameters at defined nodes to systematically generate deviation scenarios.

Risk priority number

The product of FMEA severity, occurrence, and detection ratings. Ties in RPN should be broken by severity, since severity drives consequence magnitude.

Energy trace and barrier analysis

A method identifying energy sources, the paths energy travels, and the barriers separating energy from targets. Missing or degraded barriers become hazard findings.

Sneak circuit analysis

A technique detecting unintended electrical or logic paths that produce undesired functions or inhibit desired ones without any component failure occurring.

Preliminary hazard list

An early analysis, before detailed design, using energy sources and generic checklists to identify hazards and set initial risk categories for later analysis.

Individual risk criterion

A limit on the frequency of harm to a single person, often expressed as maximum tolerable fatality probability per person-year. It is distinct from societal risk criteria.

F-N curve

A societal risk plot of cumulative frequency (F) of events causing N or more fatalities against N. Steeper curves indicate risk concentrated in larger, rarer accidents.

Mitigation hierarchy

Preferred order of risk control: eliminate the hazard, reduce severity, reduce likelihood, add detection or warning, then apply administrative controls and personal protective equipment.

Quantitative risk assessment

Expressing risk numerically, such as expected frequency of harm per year or per demand. It supports comparison against numeric criteria and cost-benefit reasoning.

Slip versus mistake

A slip is correct intention executed incorrectly, often attention failure. A mistake is an incorrect intention from flawed diagnosis or rule selection.

Performance shaping factors

Conditions that modify human error probability, including workload, time pressure, fatigue, training, procedure quality, environment, and interface design.

Human error probability

The likelihood that a required human action fails. Generic values are adjusted by performance shaping factors and by the task's detection, diagnosis, and action demands.

Error-forcing context

A condition such as ambiguous alarms, missing feedback, or conflicting procedures that makes an operator error highly likely regardless of individual skill or motivation.

Software systematic fault

A fault introduced by requirements, design, or coding error rather than random wear. It is addressed through process rigor, verification, and traceability, not redundancy alone.

Software safety integrity level

A level assigned from the severity of hazards the software could cause or fail to prevent, determining required development rigor and verification independence.

Common-cause failure

Failure of multiple redundant channels from a shared cause, such as common power, clock, library, or environment. It defeats redundancy unless diversity is applied.

Requirements traceability

Bidirectional linkage from hazard analysis through safety requirements, design, code, and verification evidence, enabling impact analysis when any element changes.

Inherently safer design

Preferring hazard elimination through minimization, substitution, moderation, and simplification over adding protective devices or administrative controls after the fact.

Proof-test interval

The time between tests verifying a safety function still works. Longer intervals raise average probability of failure on demand for hidden, undetected failures.

Management of change

A controlled process reviewing modifications to equipment, procedures, chemicals, or personnel for safety impact before implementation, including updated hazard analysis.

Lockout/tagout

Isolation of hazardous energy sources with locks and tags before maintenance, plus verification that the equipment is at zero energy state.

Functional safety standard IEC 61508

An international standard for electrical, electronic, and programmable electronic safety-related systems, defining safety lifecycle activities and safety integrity levels one through four.

ASIL determination

Automotive safety integrity level A through D assigned from severity, exposure, and controllability ratings under ISO 26262; D represents the highest integrity requirement.

Just culture

A reporting culture distinguishing human error (console), at-risk behavior (coach), and reckless behavior (sanction), encouraging disclosure while preserving accountability for reckless acts.

Leading versus lagging indicators

Leading indicators such as near-miss reports and audit findings predict future safety performance; lagging indicators such as injury counts measure outcomes already realized.