Human Error

An act of commission (doing something wrong) or omission (failing to do the right thing) that leads to an undesirable outcome or significant potential for such an outcome. For instance, installation of relief device with an incorrect set pressure would be an act of commission. Failing to notify an incoming shift team of recent process problems would be an error of omission.
Errors of omission are more difficult to recognize than errors of commission but likely represent a larger problem. In other words, there are likely many more instances in which the provision of additional information would have prevented an incident than there are instances in which the information provided quite literally should not have been given.
In addition to commission vs. omission, three other dichotomies commonly appear in the literature on errors: active failures vs. latent conditions, errors at the “sharp end” vs. errors at the “blunt end,” and slips vs. mistakes.
References: S2S(safety to safety website: Patient Safety Network, PSNet)
Management/Human Factors