Lifting operations need to be properly planned by a competent person who has both practical and theoretical knowledge, and who has experience of planning lifts.
The lifting plan needs to consider the risks involved, the equipment needed, the procedures for the lift, and who has to do what. For instance: do you know the weight of the load; is the load balanced; do you know the integrity of the lifting points; can the lift be planned to avoid people working under the suspended load; will temporary supports be needed, etc?
Maintenance work will often involve one-off lifts, or lifts that are only undertaken occasionally. Such lifts can be more dangerous because there is less familiarity with the load, or because the need for appropriate lifting and/or support equipment hasn't been properly considered in advance. For these reasons, lifting operations need to be explicitly planned in advance.
It should not be assumed that readily available lifting equipment, such as fork lift trucks, can be put to use in an ad hoc way when needed, or that the existing range of lifting accessories can be made to fit. The lifting operation may be the most dangerous aspect of the maintenance activity, and should be planned accordingly.
Lifting operations also need to be appropriately supervised, proportionate to the risk and the competence of those involved. For the reasons outlined above, lifting operations in maintenance settings are likely to require much greater supervision than the routine lifting of raw materials or finished products which are handled on a daily basis.