A PCBU proposing to excavate a trench of the depth set by WHS Regulation 306 must ensure, as far as reasonably practicable, that unauthorised access to the work area, including inadvertent entry, is prevented by securing it. In doing so the PCBU must consider the risks that unauthorised access creates and how likely it is to happen. The aim is to protect other workers on site by limiting who can get into the excavation area. This applies on top of the separate duty of whoever manages or controls the construction site to secure it, as far as reasonably practicable, against members of the public, for example close to shops, parks, schools or other public places (see 5.1).
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.