work force; personnel; workers
Refers to the people assigned to carry out a specific task or operation, often in a project or industrial context.
This project requires sufficient work force.
The construction is delayed due to a shortage of workers.
人員 is a more general term for personnel or headcount, while 作業要員 specifically refers to workers assigned to a particular task or operation.
労働力 means labor force in a broad economic sense, whereas 作業要員 focuses on the human resources for a specific job or project.
Compound of 作業 (work, operation) and 要員 (necessary personnel, required staff).