The Hierarchy of Control is a system that is used to minimise or eliminate risks associated with specific tasks or hazards.
With regard to working at height, the ultimate goal is to ensure a fall from height cannot occur. This can be achieved either by eliminating the need to work above the ground or to provide a solid elevated construction from where the work can be performed. If it is not possible to achieve this, the risk of a fall must be minimised through the application of control measures further down the Hierarchy of Control.
Eliminate the hazard. Undertake the work from ground level or from a solid construction. Redesign should be considered to eliminate the need for working at height.
Change the control measure to undertake the work from a safe zone. Relocation of equipment requiring maintenance should be considered to eliminate the requirement for the operator to enter the danger zone.
Separate the operator from the hazard by means of passive fall protection. A plant screen, barrier or guardrail will effectively prevent a fall whilst maintenance is being undertaken.
Manage the risk using an engineered control. Work undertaken using fall arrest systems requires operator training but it will prevent a fall from occurring when used correctly.
Control the risk using procedure. Control the environment using signage, demarcation line marking and operational instructions. It is important to note that the level of Hierarchy of Control is equivalent to the risk of injury, as a result of operator incompetence. A lesser control measure requires greater skill of the operator and is therefore the least preferred.