Worker Error

Webster's online dictionary defines an error as “an act or condition of ignorant or imprudent deviation from a code of behavior” and also “an act involving an unintentional deviation from truth or accuracy.” There are different possibilities and proneness to errors in the workplace by workers. Workers, like all human beings, are all prone to errors. Worker errors are responsible for various accidents in the workplace, failures, and product or service defects. About 96 percent of the errors that occur in the workplace are attributed to worker error or human error. Human error can be described as an inappropriate human act, decision, or behavior that causes or has the potential to cause undesirable events like accidents, poor [Page 1003]system performance, system failures, product/service defects, or reputational crisis.

Several factors affect workers’ proneness to error in the workplace. They include the environment, equipment design, organization, procedures, competence, and training. Worker error is responsible for many of the disasters that occur in the workplace. It has been fingered as the main cause or contributory factor in a majority of catastrophic historic events, including the Exxon Valdez accident, Bhopal chemical plant disaster, Pier Alpha, Chernobyl nuclear plant disaster, and even more recently, the Fukushima nuclear plant disaster triggered by the earthquake and tsunami but made worse by worker error. Many accident and incident reports cite human error as the primary cause. It is estimated that in the United States, worker errors are responsible for 70 percent of airplane accidents and 60 percent of nuclear plant accidents. It is also estimated that in the intensive care units of hospitals, doctor/nurse errors occur at a rate of about 1.7 per patient daily.

Worker errors can be classified as errors of commission or errors of omission. In errors of commission, the worker takes an inappropriate action that results in an unintended outcome; for example, an operator performs a step incorrectly or performs an extra step that is incorrect. In errors of omission, worker inaction results or contributes to deviation from an intended outcome; for example, an operator fails to perform a procedural step. There are three types of errors committed by humans: mistakes, lapses, and slips. They are directly related to the three stages of cognition: planning, storage, and execution. Mistakes happen when workers follow the steps in the plan but the outcomes achieved are unintended, mainly because of the original plan being wrong. Lapses are the result of memory loss or forgetfulness; they are not observable events. Slips are observable events not in accordance with the original plan. They are associated with the execution stage of cognition.

There are three levels of cognitive task processing, namely skill based, rule based, and knowledge based. Errors occur at each of these levels of human behaviors.

Skill-based error: This includes slips and lapses. It occurs usually due to misplaced attention or inattention, mainly the result of the worker becoming accustomed to what they do. The majority of the errors committed by workers in the workplace are a result of this type of error.

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