Active Error (or Active Failure)
The terms active and latent as applied to errors were coined by Reason. Active errors occur at the point of contact between a human and some aspect of a larger system (e.g., a humanâ€“machine interface). They are generally readily apparent (e.g., pushing an incorrect button, ignoring a warning light) and almost always involve someone at the frontline. Active failures are sometimes referred to as errors at the sharp end, figuratively referring to a scalpel. In other words, errors at the sharp end are noticed first because they are committed by the person closest to the patient. This person may literally be holding a scalpel (e.g., an orthopedist operating on the wrong leg) or figuratively be administering any kind of therapy (e.g., a nurse programming an intravenous pump) or performing any aspect of care. Latent errors (or latent conditions), in contrast, refer to less apparent failures of organization or design that contributed to the occurrence of errors or allowed them to cause harm to patients. To complete the metaphor, latent errors are those at the other end of the scalpelâ€”the blunt endâ€”referring to the many layers of the health care system that affect the person "holding" the scalpel.