Features of Decision-Making in Process Control Tasks: The Relevance of the Work Context

Abstract:

This paper is centred on evaluating some significant features of decision-making in process control tasks. The study was carried out in a petrol refinery, specifically, with distillation console operators. Operator verbalisations were recorded during the completion of two specific tasks and later categorised by raters using a list of cognitive categories. The inter-rater reliability was calculated together with qualitative evaluations of the main overlaps among the categories. From the raters’ evaluations, flow diagrams were drawn that represented the plans and tactics developed by operators and the implied cognitive processes (evaluation, prediction, action, etc.). We found that the operators began the tasks with a primary global situation assessment that determined the choice of whether to cope with the task ‘step by step’ or ‘globally’. The results showed two patterns of decision sequences made in normal adjustment performance or in problem situations. Other findings are related to the importance of characteristics such as prediction, anticipation, feedback and the role of the alarms selected by a situation assessment and individual characteristics.