Glossary · Hazards and harm
Human error
In machine safety, human error is an action or omission that differs from the intended or required behavior. It must be considered in system design, without treating people as the sole control against a hazard.
- Machine safety
- Human factors
In one sentence
Human error is a foreseeable deviation from intended behavior; machine design must tolerate it instead of relying on people as the only control.
Example
An operator selects the wrong recipe on a filling line because two similar entries sit next to each other on the HMI; the redesign adds a confirmation step instead of relying on a note in the manual.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
- Human error types and troubleshooting: from slips, lapses and mistakes to recovery informationTransitional topicHow do the error types of James Reason and Jens Rasmussen's skill-, rule- and knowledge-based behavior help design troubleshooting and recovery information?UKDeutsch
- Cognitive psychology in technical communication: theory, application and the bridges between themTransitional topicWhat is the difference between cognitive psychology as theory and its application in documentation, and how do the two fit together?UKDeutsch
- Task analysis: one task, three lensesIs task analysis one method, or are technical, collaborative and cognitive task analysis different things?UKDeutsch
How it applies
- Machine safety: ISO 12100 asks designers to consider reasonably foreseeable misuse, which includes foreseeable human behavior. Design measures and safeguards should tolerate slips, lapses and mistakes; the hierarchy of controls ranks procedures and training below design.
- Human factors: Errors have causes: poor ergonomics, unclear displays, time pressure, fatigue. Analyze these conditions rather than stopping at “operator error”.
- Technical documentation: Instructions reduce errors only if they are usable in the situation. Test critical procedures with real users, and do not present a warning as the main measure against a foreseeable error.
- Evidence: An incident report that ends with “human error” is incomplete. Record the contributing design and organizational factors and feed them into change control.
Human error vs. bypass behavior
Human error is unintended. Bypass behavior is a deliberate deviation. Both need design answers, but different ones.