RESUMEN
Today in most of the work environments, such as nuclear, military and chemical industries, human error may result in catastrophic events. A common characteristic of large technological systems is that massive amounts of potentially dangerous materials are kept in one single unit controlled by control room operators. A control room is indeed the heart of a system of this type and any error in task performance by the operators may have undesirable consequences which could never be compensated. In this study we aimed to identify and assess human errors in the control room of the Aromatic Unit of Bouali-Sina Petrochemical Company, Iran using the CREAM method. This was a cross-sectional and analytical-descriptive study carried out in the control room of the Aromatic Unit of Bouali-Sina Petrochemical Company, Iran with 39 operators. After a job analysis by the hierarchical task analysis [HTA], probable control modes and cognitive failure probability were determined for occupational tasks using the basic and the extended CREAM methodologies. Based on the results of the basic CREAM method, control modes for the tasks of action, Boardman and shift control supervisor were determined as Opportunistic Control mode, while for the task of control room head it was obtained as Tactical control mode. With regard to the error types, the following results were obtained on the basis of the extended method of CREAM: execution failure [51.70%], interpretation failure [19.55%], planning failure [14.94%], and observation failure [13.81%]. The basic CREAM method showed the common performance factors [CPCs] leading to reduced performance reliability to be the number of simultaneous tasks, time of day [circadian rhythm], and adequacy and quality of training and experience. These factors caused the operators to choose an opportunistic control mode. In addition, based on the extended CREAM method results, the most noticeable cognitive failure was execution failure. In addition, the most important cognitive activities related to the control process in the control room were communication, execution, diagnosis, monitoring, and planning. Based on these findings, providing instructions and guidelines for work procedures, holding training courses, shift work scheduling, optimization of the communication systems and modifications in the control software are essential to minimize human errors in the Bouali Sina Petrochemical Company control room