Human Factors Analysis and Classification System¶
Classify an operational accident through four ordered causal strata— organizational influences, unsafe supervision, preconditions for unsafe acts, and unsafe acts—so investigation climbs past the visible operator error and routes intervention to the layer that generated it.
Core Idea¶
The Human Factors Analysis and Classification System (HFACS) is an accident-analysis framework that classifies contributing conditions into four causally ordered layers: organizational influences, unsafe supervision, preconditions for unsafe acts, and unsafe acts. It directs inquiry upward from visible operator behavior toward latent system conditions. A case is coded across the four-layer taxonomy, cross-level pathways are traced, and intervention responsibility is allocated to the level capable of changing the generating condition. The framework's value lies in disciplined classification, not merely the slogan “systems matter.”
Scope of Application¶
Aviation, medicine, mining, and maritime safety all use or adapt HFACS, but they import the same safety-science framework. Stripping accident investigation and its named strata leaves generic multilevel causal analysis.
Clarity¶
Swiss-cheese models describe aligned defensive failures without supplying the same coding taxonomy. Root-cause analysis is a broader family. Unsafe Supervision is one HFACS stratum, not the entire framework. Human error is an outcome category, not a multilevel classifier.
Manages Complexity¶
The abstraction turns a scattered family of cases into one role-based test: identify the required elements, test their relation, and reject the classification when a constitutive commitment is missing.
Abstract Reasoning¶
Use the structural signature rather than the label, then challenge the nearest counterexample. A report that simply blames both “management” and “the pilot” without coding causal pathways through the four layers is not HFACS analysis.
Knowledge Transfer¶
Aviation, medicine, mining, and maritime safety all use or adapt HFACS, but they import the same safety-science framework. Stripping accident investigation and its named strata leaves generic multilevel causal analysis.
Example¶
A case qualifies only when the definition and every load-bearing role remain present. A report that simply blames both “management” and “the pilot” without coding causal pathways through the four layers is not HFACS analysis.
Relationships to Other Abstractions¶
Current abstraction Human Factors Analysis and Classification System Domain-specific
Parents (5) — more general patterns this builds on
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Human Factors Analysis and Classification System is part of Active Failure Domain-specific
Active failure supplies the sharp-end unsafe-act constituent stratum of the staged HFACS whole.
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Human Factors Analysis and Classification System is part of Organizational Influence Failure Domain-specific
Organizational influence failure is the apex constituent stratum of HFACS.
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Human Factors Analysis and Classification System is part of Precondition for Unsafe Act Domain-specific
Preconditions for unsafe acts are the third constituent stratum of HFACS.
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Human Factors Analysis and Classification System is part of Unsafe Supervision Domain-specific
Unsafe supervision is the second constituent stratum of HFACS.
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Human Factors Analysis and Classification System is a decomposition of Swiss Cheese Model (Layered Defense with Aligning Holes) Prime
HFACS is the human-and-organizational accident-investigation form of the Swiss-cheese model, adding a fixed four-level taxonomy and layer-indexed remedies.
Hierarchy paths (102) — routes to 11 parentless roots
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Conjunctive Path Activation → Causality → Dependency
Show alternative paths (101)
- Human Factors Analysis and Classification System → Unsafe Supervision
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Context
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Conjunctive Path Activation → Causality → Dependency
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Conjunctive Path Activation → Causality → Dependency
Show 93 more paths
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Conjunctive Path Activation → Causality → Dependency
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Self Checking
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Optimization
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Heavy-Tailed Distributions
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Recurrence
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Mobilization → Latent Realizable Capacity
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
- Human Factors Analysis and Classification System → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Trade-offs → Constraint
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Reserve → Economy Of Force → Allocation → Scarcity → Constraint
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Representation → Abstraction
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
- Human Factors Analysis and Classification System → Organizational Influence Failure → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
- Human Factors Analysis and Classification System → Precondition for Unsafe Act → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- Human Factors Analysis and Classification System → Active Failure → Latent Condition → Swiss Cheese Model (Layered Defense with Aligning Holes) → Defense In Depth → Redundancy → Two-Store Architecture → Caching → Locality Of Reference → Spatial Indexing → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
Not to Be Confused With¶
Swiss-cheese models describe aligned defensive failures without supplying the same coding taxonomy. Root-cause analysis is a broader family. Unsafe Supervision is one HFACS stratum, not the entire framework. Human error is an outcome category, not a multilevel classifier.
Notes¶
(Canonical first draft; queued for Claude house-style re-authoring and citation review.)