WORKLOAD ANALYSIS

A CONTROL ROOM SHOULD BE A WELL OILED MACHINE

A complex area of human factors engineering that employs measurement and prediction methods to control room operations, to optimize human performance, and ultimately, safety.

What is a workload analysis and why might you need one?

Many factors contribute to major accidents in energy, processing, mining or manufacturing, and workload issues are among the top 10 culprits. Your mission-critical operation camp or control building needs the right people in the right place at the right time to operate safely—too low a workload can result in confusion, boredom and loss of situational awareness, and too high a workload can result in missing critical information and adversely affecting performance in a high workload event, such as an abnormal situation. A workload analysis (WLA) can determine the optimal workload, allowing your plant to strike the perfect balance of safety and productivity.

Mental and physical demands on operators can be taken into account, and analyzed. A basic timeline analysis enables us to understand how tasks are undertaken over time. The cognitive activity required for each task can be classified, and include visual, auditory, cognitive and psychomotor (VACP) aspects. This enables us to understand where there may be task conflicts and consider different ways of doing the task, or sharing the task in different ways.

For example, if an abnormal situation arises at a plant having to do with, say, pressure readings, an operator may be inundated with multiple VACP elements. These can include screen signals, alarms, radio transmissions, phone calls, pulsating lights, and other operators relaying information. Under these conditions an operator has to assimilate the information, diagnose the problem and plot a course of action. A lot is at stake in a situation like this. Furthermore, the ideal workload is between 50% and 70% of maximum. If your operators are already at 90% on any given day, the cognitive demand is too great and error is more likely to occur. A workload analysis will determine critical deficiencies in operator workload planning.

There are different methods that can be used to assess staffing arrangements which take into account many factors including the physical and logistical realities. Is the operator always in the control room, or are they also in the field? Not all rooms are permanently manned 24/7. If the operator has to walk a half-mile from the field to the control room, an abnormal situation may escalate to an explosion situation during the time it takes to physically cover that ground. The staffing assessment looks for all those potential scenarios, and pinpoints weaknesses in the system. Effectively, it looks at whether there are enough people with the right capabilities and resources to cope with a high workload situation. There are two parts to the staffing assessment; physical assessment which is a scenario based assessment; and the ladder assessment which uses 16 criteria to benchmark the organization against industry best practice, including factors such as teamwork, communication, situational awareness, and competence.

Other workload analysis techniques

A WLA may use secondary task performance techniques, which simulates a primary task in a controlled environment, then adds and subtracts tasks to see how performance degrades, how and when error might occur and how reaction time might change.

Another key technique is subjective workload measurement, whereby operators are simply asked to rank their workload before, during and after the tasks required of them. The most well-known of this category of techniques was developed by NASA and is known as the Task Load Index (NASA-TLX).

A workload analysis is essentially part of human factors engineering that seeks to address risk mitigation proactively through analyzing and addressing weaknesses in the control room system. It is an investment in process optimization that in the long run can avert potential litigation, and save time, money and lives.

Learn more about why BAW Architecture is the leader in 24/7 mission-critical control building design, or contact us to start a conversation.

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