When using fall-arrest systems, specialist assistance may be necessary to select appropriate equipment, provide effective training in use and inspection, and develop an emergency retrieval plan to recover a person suspended in a fall-arrest harness. People suspended by a fall-arrest harness for short periods of time may suffer serious health effects, or may have incurred injury during the fall prior to the fall-arrest device deploying.
A tool generally is any physical item that can be used to achieve a goal, especially if the item is not consumed in the process. Informally, it also describes a procedure or process with a specific purpose.
The idea of a simple machine originated with the Greek philosopher Archimedes, who studied the machines, lever, pulley, and screw, and discovered the principle of mechanical advantage in the lever. Furthermore, the Greek Philosophers defined the classic five simple machines, which were used to roughly calculate the mechanical advantages.
Administrative controls use systems of work to reduce risk by providing a framework of expected behaviours. Examples are rotation of staff to reduce exposure to a hazard, or a documented safe system of work, such as lockout tagout. These types of controls rely on extensive instruction, information, training and supervision.