Impact of Functional and Schematic Overview Displays on Console Operators’ Situation Awareness

Abstract

Console operators in process plants have to maintain a high level of situation awareness to operate the plant safely, effectively, and efficiently. An overview display is one of the primary displays in a control room that operators monitor to gain and maintain an understanding of the plant. In this study, the authors evaluated operator performance using two overview display formats. The first format, characterized as a functional design, included qualitative, graphical indicators for process parameters and organized the position of the indicators on the basis of functional relations of the process equipment. The second format, characterized as a traditional schematic display, showed connecting process lines between equipment and numerical fields to present process information. Both displays contained the same indicator values. Eighteen plant operators used both display formats to monitor a crude unit process for process parameters that deviated from normal values. We measured operators' situation awareness using think-aloud protocols and situation awareness global assessment technique, subjective workload, and usability ratings. Results indicated that operators' situation awareness was significantly higher when they monitored the process on a functional display compared with a schematic display. Their subjective workload and usability ratings also favored the functional overview display format. Implications of the findings for continuous process control and overview display design are discussed.

Perceived stress in human–machine interaction in modern manufacturing environments—Results of a qualitative interview study

“…This so called "situation awareness" decreases as systems become more complex (Endsley, 2015(Endsley, , 2017. Situation awareness increases when the system design allows for an adequate representation of the system status (Endsley, 1995b;Tharanathan, Bullemer, Laberge, Reising, & Mclain, 2012), which reduces operating errors (Liao & Chang, 2011) and increases the subjective quality of the human-machine interaction (Skjerve & Skraaning, 2004). Compared with relations of situation awareness and performance measures, relationships between situation awareness and subjective experience are less well studied.…”

Evaluating Control Room Interface Design and Automation in Petrochemical Operations

“…The subsystems are organized consistently with their functional relation to the facility (Tharanathan et al, 2010). Tharanathan et al (2012) examined console operator SA in an overview display using both a functional and schematic interface. They found that operator's SA was significantly higher when they monitored processes on the functional display in comparison to the schematic display.…”

Presenting Trends In Petrochemical Process Control Systems

“…There has been a steady evolution of the technology used in a supervisory control in many control rooms, with operators responsible for the supervision of about 200 to 300 control loops. If the control system cannot maintain target values for process parameters then the operator has to intervene to keep the system from exceeding the safe operating limits [4]. It has been found that a large number of errors that occur in supervisory control systems can be attributed to human error, rather than a failure by the control automation [5].…”