167: Unrealistic Monitoring Requirement
Definition/Typical Issues
Were personnel required to monitor multiple variables at once, causing overload or failure to notice important information? Could the error be attributed to loss of alertness because of the excessive length of a monitoring task?
Examples
Example 1
- An operator given the responsibility for temporarily monitoring the alarms for another unit allowed a tank to overflow. He acknowledged the audible level alarm for the tank, which resulted in muting of the horn. He meant to return to the problem; however, an alarm from one of the other systems sounded, and his immediate attention was required there. The tank associated with the first alarm overflowed before he was able to take appropriate action.
Example 2
- A radar operator was given the responsibility of monitoring a screen for planes during an entire 8-hour shift. During a normal shift, no planes enter his radar space. As a result of a decrease in vigilance, the operator failed to identify an intruder into his air space late in his shift.
Example 3
- Because of reductions in staffing levels, an operator was given the added responsibility of monitoring the operation of the flare system that serves several units, including his own. The operator can easily perform these duties during normal operations; however, during nonroutine modes of operation (e.g., startup), the operator is unable to monitor the flare system because of increasing responsibilities in his own unit. Inattention to the flare system caused the flare system to fail to function properly, allowing a release of unburned process material to the atmosphere.
Example 4
- Eight maintenance tasks were in progress at the same time. The control room operator had to perform some steps for each of these tasks. He was to transfer the contents of tank A to tank B to support one of the maintenance tasks. While he was involved with another task, he lost track of the tank level and tank B overflowed.
Example 5
- The audible alarm on the toxic gas detector was inoperable. An operator was assigned to watch the toxic gas meters for an entire 8-hour shift to detect a toxic gas release. The operator failed to notice a release when it occurred.
Typical Recommendations
- Automate the system so that personnel are not required to monitor several variables simultaneously. However, provide enough employee interaction with the system to keep personnel alert.
- Do not place workers in situations requiring extended, uneventful vigilance.
- Ensure that staffing levels are adequate for normal, abnormal, and emergency operations.
Cross-References
| Version 10 Element(s) | |
|---|---|
| Node ID | Node Name |
| 157 | Unrealistic Monitoring Requirements |
| Maritime Element(s) | |
|---|---|
| Node ID | Node Name |
| 147 | Unrealistic Monitoring Requirements |