Critical Job Function vs. Critical Task
A critical job function is the main purpose and primary pay factor for a job, what the role fundamentally exists to accomplish.
Critical tasks are the activities workers must perform to carry out their critical job function(s).
This hierarchy matters for requirements analysis. Physical demands, cognitive requirements, and environmental conditions are measured against critical tasks, not peripheral duties. A job may occasionally require heavy lifting, but if that lifting isn’t part of a critical task, it doesn’t define the job’s strength requirements.
The distinction prevents over-specification. Not everything a worker might do defines what the job requires. Requirements attach to what’s essential, not incidental.