Evaluation of presentation of information for process control operations

In an experimental process control simulation study two operators performed monitoring and control operations including safety critical tasks that required parallel processing of information distributed over different functional mimic displays. The assignment of mimic displays to Visual Display Units (VDUs) was experimentally varied by allowing one or two VDUs for mimic presentation. The study revealed no evidence for differences in task performance during normal process control operations. During abnormal operations, however, detrimental effects both on performance and work load were observed. Having only one VDU available for mimic display revealed either a lower level of performance (time for fault management) and/or a higher level of emotional work strain. It is concluded that decisions on the number of VDUs necessary for effective and efficient process control must refer to the tasks to be performed and the presentation of information necessary for a safe, effective and efficient task performance under critical, but not only normal conditions.