Final answer:
An unfavorable direct labor efficiency variance may occur when employees or supervisors have not received proper training.
Step-by-step explanation:
When employees or supervisors have not received proper training, an unfavorable direct labor efficiency variance may occur.
This variance is a measure of the difference between the actual amount of direct labor hours used and the standard amount of direct labor hours that should have been used. It is an indication that employees or supervisors are not working efficiently or effectively, leading to higher labor costs.