Human Errors and Human Reliability¶

Status: emerging
Last updated: 2026-05-31
Sources: 9781119636113.Ch20.Pdf
Tags: [human-error, human-reliability, system-safety, error-taxonomy, error-management, safety]

Summary¶

Human error is a generic term for occasions when a planned sequence of mental or physical activities fails to achieve its intended outcome without the intervention of chance (Liu et al., 2021, citing Reason, 1990). The chapter reviews the prevalence of human error in safety-critical domains, competing definitions, the cognitive reasons humans err, and measures for managing error and improving reliability. It draws heavily on Reason's framework, distinguishing error types such as slips, lapses, and mistakes and separating latent from active failures.

Body¶

Context¶

Liu et al. (2021), in their handbook chapter on Human Errors and Human Reliability, review the prevalence of human error in safety-critical domains, competing definitions of error, the cognitive reasons humans err, and measures for managing error and improving reliability. The chapter draws heavily on Reason's framework, distinguishing error types and separating latent from active failures. Within this knowledge base the article is the safety-and-reliability anchor: it supplies the error taxonomy that Accident And Incident Investigation applies after the fact and that Hfe Audits and Task Analysis aim to forestall, and it connects to the automation-induced error risks examined in Supervisory Control Of Automation and the design countermeasures in Warnings And Hazard Communication.

Key Points¶

Human error contributes substantially to accidents across working environments. The aviation industry, where safety is highly valued, has abundant accident records, with one early estimate attributing approximately 70% of aircraft accidents and incidents to human error (Feggetter, 1982, cited in Liu et al., 2021) (PDF p. 1, orig. p. 514). This prevalence motivates the study of why humans err and how systems can be made more reliable, while raising the question of what exactly counts as human error.

The chapter contrasts two definitional traditions. Reason's (1990) definition treats error as a generic term encompassing all occasions in which a planned sequence of mental or physical activities fails to achieve its intended outcome, where the failures cannot be attributed to chance; here the key judgment is whether the intended outcome is achieved. A consequence-based definition from Sanders and McCormick (1993, cited in Liu et al., 2021) treats error as an inappropriate or undesirable decision or behaviour that reduces or could reduce effectiveness, safety, or system performance, counting potential undesirable consequences as error even when none result (PDF p. 2, orig. p. 515).

Error types and the system perspective follow Reason's framework. Liu et al. distinguish slips and lapses — failures in the execution of an intended action — from mistakes, which are intended actions with unintended consequences (Reason, 1990) (PDF p. 3, orig. p. 516). They stress that error is often a consequence rather than a cause, and that latent errors, which do not have immediate effects, are common (Reason, 1997, cited in Liu et al., 2021) (PDF p. 2, orig. p. 515). This systemic view shifts attention from blaming individuals toward the conditions that make errors more likely.

For error management, Liu et al. organise countermeasures into technological, administrative, and cultural measures, reflecting the multilevel nature of error control (PDF pp. 22–23, orig. pp. 535–536). A final section addresses human error in emerging areas, considering the opportunities and challenges that new technologies present for both creating and mitigating error (PDF p. 24, orig. p. 537).

Conclusion¶

Liu et al. (2021) conclude that human error is best understood systemically rather than as individual failing. Following Reason, error is frequently a consequence of latent conditions, so improving reliability depends on technological, administrative, and cultural countermeasures together, with new technologies posing fresh challenges for both creating and mitigating error.

References¶

Feggetter, A.J. (1982) 'A method for investigating human factor aspects of aircraft accidents and incidents', Ergonomics, 25, pp. 1065–1075. To be validated.

Liu, P., Zhang, R., Yin, Z. & Li, Z. (2021) 'Human Errors and Human Reliability', in Salvendy, G. & Karwowski, W. (eds.) Handbook of Human Factors and Ergonomics. 5th edn. Hoboken, NJ: John Wiley & Sons. liu2021humanerror

Reason, J. (1990) Human Error. Cambridge: Cambridge University Press. To be validated.

Reason, J. (1997) Managing the Risks of Organizational Accidents. Farnham: Ashgate Publishing Ltd. To be validated.

Sanders, M.S. & McCormick, E.J. (1993) Human Factors in Engineering and Design. 7th edn. New York: McGraw-Hill. To be validated.

Open Questions¶

How should consequence-based and outcome-based definitions of error be reconciled when assessing reliability?
How do new technologies and automation shift the balance between latent and active failures?