One of the main factors which push human to accidentally make a mistake is “Mental Workload”. Mental Workload is the demands in the relation to the amount of resources the operator is will or able to allocate.
“Overload” is when we work under a lot of pressure such as time pressure or high requirement. “Underload” is the working frequently, and need just simple narrow requirement. The key to reduce the Overload or Underload is to balancing between working hours and rest. The manager should also be responsible to manage between jobs and employees.