How does staffing shape operator performance?

Performance-Shaping Factors Series

NEWSLETTER ARTICLE

Lesson 4 - Staffing

There is not a single way to answer both those questions. Different job types and operational modes require tailored approaches. What's suitable for one position in a specific mode might be unsuitable for another. The bottleneck or determinant of staffing can differ significantly based on varying job characteristics.

Do Our Staffing Levels Ensure Safety?

“Better to have too many than too few” is an adage often heard. It is only minimally correct. Low workload can be as detrimental to performance as high workload.1 Surprisingly, having an excess of positions can create abnormal situations and lead to poor performance when such incidents occur. If positions exist beyond that which is needed for safe operation, then a greater number of people have potentially been put in harm’s way. As tragic as an injury or fatality is, that tragedy is compounded if it happens to someone who wasn’t required to be present.

So, the primary question we must answer is: How do we determine the right staffing levels for ensuring safe operations? At the most basic level, there are two types of positions and two modes of operation as in Figure 2.

Console Positions
Staffing for these roles should be based on steady state workload. However, many a console operator is a "bored" operator. Why does the company accept such low workload? The often-heard response is that the extra console personnel are needed in case an upset occurs, with floods of alarms, multiple graphics to be examined, and numerous control changes. I hate to be the bearer of bad news, but that’s management’s fault for allowing all this to occur in an upset. Manage the alarms, automate the actions, and create better displays. Management has determined the annual cost of an additional console position (NPC approximately $3-4 million?) is less than fixing the system. Unfortunately, the negative effect of low workload is the most pronounced with console operators. They need to stay actively engaged to handle the sudden ramp-up in workload during an upset. So not only is there the cost, but there is also a significant risk of “operator error” should an incident occur.

Field Positions
Staffing of field positions should be based upon the number of operators required to bring the unit safely to a stable condition in response to a severe process upset. Enough operators must be present to protect people (both in the plant and out), the environment, and corporate assets. Operational interruptions due to insufficient staffing, resulting in prolonged downtime or delayed restarts, necessitate a cost-benefit analysis by management. Operators often comment that it is harder and takes more people to keep the unit up and running than it does to shut it down. That may be true. But keeping it running is a choice. At some point, shutting down becomes inevitable due to factors beyond the plant's control or the sheer difficulty of keeping it running. Being able to land a plane is more important than being able to have it take off. So minimum staffing is that needed to bring the unit safely to a stable condition.

Do Our Staffing Levels Ensure Efficiency?

The secondary question asks whether the field staffing levels required for responding to process upsets can manage the day-to-day work required on a unit. In addition to operating equipment, operators are needed to prep equipment for maintenance, collect process samples for laboratory analysis, be the eyes/ears of the console operator, and inspect equipment for signs of fatigue or failure. If insufficient operators are present, then tasks don’t get done.

If the minimum number of operators for an upset is greater than that needed for day-to-day, all is fine. However, if more operators are needed for day-to-day than upset response (possibly due to automating some of the upset tasks), then plant management has some options. Daily workload is rarely the same over the course of the entire day/week. Take maintenance, which tends to be higher on dayshift, Monday through Friday. How different is the workload when maintenance is present than when not? 

Many plants are finding the workload sufficiently high and staff differently for days versus nights. In a recent project, Beville analyzed the impact of using a day assistant on (24/7) unit operator workload. The results indicated that differential staffing kept their operators’ maintenance load closer to industry average (Figure 3). As long as the night staffing is above the number needed for managing abnormal situations, then having different staffing levels is more efficient.

The Short Answer

Determining the appropriate staffing levels is challenging due to the variability between upset and steady state workload (Figure 4).

Consoles should be designed to handle upset conditions, with a steady state workload sufficient to keep the operator engaged. Process units must always have enough field staffing 24/7 to safely bring the unit to a stable condition in response to an upset. Ideally, daily steady state workload is higher than this minimum number.

35+ Years of Experience and Data

At Beville, we have developed techniques to quantify and address workload and staffing challenges. Beville’s databases contain detailed workload data on over three thousand positions, encompassing board and field roles in production facilities, refineries, pipelines, and chemical plants. By quantifying the workload, we enable objective decision-making, free from the emotions that often cloud staffing discussions.

By adopting a data-driven approach, you can determine staffing levels that guarantee safe and efficient operations. Let us know if you’d like to learn more about our techniques and how they can benefit your plant.

[1] Young, M. and Stanton, N. “Malleable Attentional Resources Theory: A new explanation for the effects of mental underload on performance”. Human Factors, Vol. 44, No. 3, Fall 2002, P365-375.

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