In the modern control room, the operator will generally have some of the following tasks:
1. Start up/stop the system
2. Control, manoeuvre, and regulate
3. Check, monitor (act only when there is a fault)
4. Keep records and report
5. Repair and maintain
6. Plan, programme, and analyse
Different types of skill and knowledge are required in order to do these tasks. Job skills may be divided roughly into seven areas. The first, perceptive skill, is concerned with the ability to notice and distinguish signals from complex patterns. These are normally light or sound signals. One example of a difficult perceptual task is radar work. Many inspection tasks, such as the supervision of electronic circuit room work, also set high requirements on perceptual ability. In control room work, hearing is the sense traditionally used to bring small changes in the condition of the process to the operator’s attention.
The demands on perception in control room work are sometimes relatively high. They can, however, be reduced if instruments, VDU screens, and light fittings are designed to provide an overall solution. It is important that a good perceptual solution not only enables the various information-giving devices to be easily seen but also that their logical relationships enhance understanding of the process.
The demands on different forms of cognitive/thinking ability vary considerably in different types of control rooms. Sometimes the requirements are very small, for example, when the control room tasks are mainly supervisory. When the job involves planning and analysis work, the demand on mental processes may be considerable. It is important for these types of demands to be matched to the operator’s abilities, earlier experience, and knowledge. It is also an advantage if the demands are changed in line with the increase in experience over time.
Many modern computerised control rooms have reduced the demands on the memory and its ability. This is because the computer can store any information, tabulations, and coefficients to which the operator may need access. However, understimulation can occur because of the special demands of control room work that often involve long periods of low activity. This in turn requires vigilance ability, the ability to maintain a certain form of alertness despite the soporific nature of the work. In repair and maintenance work, what is known as diagnostic skill is often needed. There are different strategies for looking for faults in technical systems; one can, for example, test different components according to the level of probability that they are faulty. Another strategy is first to test half of the components, and then to carry out tests on the others. Diagnosis skill is often defined as:
1. The ability to find suitable guidelines.
2. The ability to interpret the guidelines in relation to the situation in hand.
3. The ability to select effective testing and searching strategies.
Diagnostic ability is associated with the operator’s breadth of job skill. Repairing different faults, even electrical ones, requires not just electrical knowledge but also mechanical knowledge. The requirement for sensorimotor ability is considerable in many manual jobs and in vehicle driving. The need for motor ability is greatest in craft and purely manual tasks. Control room work does require a certain degree of motor and sensorimotor abilities, but the motor requirements are relatively limited.
In certain types of control room work, where the operator starts and stops the process directly and where the process speed is relatively slow, the demand for control skill can be very high. Control skill can be seen as a skill that people possess to varying degrees depending on their experience and other factors. It is thought that the most skilful control operators have some form of ‘intuition’ of what is the most suitable control movement to make or not make. It is not always thought, however, that it is such people who have the best ability to control and manoeuvre the process. This ‘intuition’ may be described as the operators having their own conceptual (mental) model of the relationships between control movements and the final result. This conceptual model is a simplified and schematic description of the actual functions in the process (see Chapter 2).