What is the ruling on some workers in the iron and steel factory sleeping during official working hours while there are pending tasks?

Every job has its own specific custom. Minor breaks for drinking tea, eating, and similar activities that do not disrupt the work are excused. A person has a certain capacity and cannot work beyond it without difficulty. Customs vary according to the nature of the work; some jobs may require a break for the employee. The rule in this matter refers back to custom. One must fear Allah and perform the work as fulfillment of the contract, for Allah Almighty says: "O you who have believed, fulfill [all] contracts."