Workload has long been considered as one of the important factors for personal functions and malfunctions, particularly in complex systems. Undertaking operations in workstations of such systems usually entails complex tasks and poor cognitive performance of their operators may contribute to human error and critical subsequent consequences. Although many studies have investigated the effects of workload on the cognitive performance, there is a gap for specific jobs and operations such as control room operation. This paper then aims to determine that what dimensions of the workload has more impact on cognitive performance of a combined cycle power plant (CCPP) Control room operators. Control room operators from two CCPPs participated (n = 95) in this study. Hierarchical task analysis (HTA) was employed to perform the job analysis. To assess the perceived workload, NASA Task Load Index (NASA-TLX) was performed at the end of the work shift. The participants were subjected to three cognitive performance tests including sustained attention, simple reaction and working memory at the beginning and end of the work shift. The values of mental demand on check and control tasks (92.17 ± 4.38), decisions about abnormal conditions (90.16 ± 5.71) and reporting (85.09 ± 3.25) were high. The task of communication and coordination in terms of temporal demand (71.66 ± 7.3) and performance (68.04 ± 4.92) had higher values compared to other tasks. The highest weighted workload (84.27 ± 6.48) was also attributed to the task of checking and controlling. Sustained attention and working memory were more susceptible to excessive workload among CCPP control room operators.

长期以来，工作量一直被认为是个人功能和故障的重要因素之一，尤其是在复杂的系统中。在这样的系统的工作站中进行操作通常会带来复杂的任务，操作员的认知能力差可能会导致人为错误和严重的后续后果。尽管许多研究已经调查了工作量对认知能力的影响，但是在特定的工作和操作（例如控制室操作）方面仍存在差距。然后，本文旨在确定工作量的哪些方面对联合循环电厂（CCPP）控制室操作员的认知性能具有更大的影响。来自两个CCPP的控制室操作员参加了会议（n = 95）。分层任务分析（HTA）用于执行工作分析。为了评估可感知的工作量，在工作班次结束时执行了NASA任务负荷指数（NASA-TLX）。在工作开始和结束时，参与者接受了三个认知性能测试，包括持续注意力，简单反应和工作记忆。对检查和控制任务的心理需求（92.17±4.38），对异常状况的决策（90.16±5.71）和报告（85.09±3.25）的值很高。与其他任务相比，就时间需求（71.66±7.3）和绩效（68.04±4.92）而言，沟通和协调任务的价值更高。加权工作量最高（84.27±6.48）也归因于检查和控制任务。