Human factors: Workload

Why is workload important?

Humans have limited capability for processing information (such as from displays, alarms, documentation and communications), holding items in memory, making decisions and performing tasks. Excess workload can result in human performance issues such as slower task performance and errors such as slips, lapses or mistakes. It should also be noted that underload can also lead to human performance issues such as boredom, loss of situation awareness and reduced alertness. Workload issues may be more relevant in times of downsizing or temporarily during peaks (such as incidents or turnarounds).

Workload is related to competence (eg some tasks can require less processing in experienced personnel), working hours/patterns (eg underload in nightshift control room operators), organisational change (where tasks or roles are changed) and staffing levels. Workload may be higher in some industries/roles where there is an inadequate supply of skilled staff. A high (or perceived high) workload not only adversely affects safety, but also negatively affects job satisfaction and, as a result, contributes to high turnover and staff shortages.

An assessment of workload may be required if you wish to determine whether you have sufficient staff; if capacity exists for additional tasks, or whether personnel can cope with emergencies, incidents or process upsets.

Workload should be assessed if new tasks, equipment, or systems are introduced; or where changes are made to roles and responsibilities.

Key principles in workload