Situation awareness acquired from monitoring process plants – the Process Overview concept and measure

Abstract

We introduce Process Overview, a situation awareness characterisation of the knowledge derived from monitoring process plants. Process Overview is based on observational studies of process control work in the literature. The characterisation is applied to develop a query-based measure called the Process Overview Measure. The goal of the measure is to improve coupling between situation and awareness according to process plant properties and operator cognitive work. A companion article presents the empirical evaluation of the Process Overview Measure in a realistic process control setting. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA based on data collected by process experts.

Practitioner Summary: The Process Overview Measure is a query-based measure for assessing operator situation awareness from monitoring process plants in representative settings.

Keywords:

• Situation awareness
• process control
• monitoring
• domain-specific
• measurement

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Translated ‘SA of Area Controllers within the Context of Automation’ from German.

2. Although process plants are mostly closed to external disturbances, they can be dramatically impacted by external events such as the tsunami that incapacitated the Fukushima nuclear facility.

3. Field operators are usually responsible for managing specific equipment in the plant. For instance, control room operators often ask field operators to check the operations of a valve. Field operators also inform control room operators if they witness equipment malfunction in the plant.

4. We can relate to this experience in our daily activities. For instance, time perception for a conversation is content-based rather than clock-based. Consequently, people can generally recall a portion of conversation more accurately by referring some content rather than time markers. (e.g. What did we talk about after discussing the dinner menu? What did we talk about fifteen minutes ago?).

5. The general criteria are that the changes should be (i) observable on displays, (ii) detectable on plots of appropriate scale, (iii) large compared to the baseline established by normal simulator runs, (iv) illustrative of predominant parameter trends and (v) enclosed in an approximately three-minute interval (for past and future queries).

6. The alternatives of increasing, stayed the same and decreasing are not applicable to describing parameter behaviour in the present because a parameter change must be described with respect to a time period.

7. Note that SAGAT does employ process experts to determine reference answers to queries that cannot be obtained from the simulators including Level 2 – Comprehension questions (Endsley, 2000).

8. Specifically to SAGAT and SACRI that include prediction queries, reference keys for prediction queries may be collected by running scenario trials without operator intervention. This method has two caveats. First, the method is only applicable at the end of the scenario when operators no longer affect parameter changes. Second, the method may still require experts to account for process dynamics (e.g. a very slow increase in reactor power).