Officers, such as company directors, have to exercise due diligence so the PCBU meets its obligations under the WHS Act and Regulations. For excavation work this includes taking reasonable steps to see that the business has, and actually uses, suitable resources and processes for eliminating or minimising the health and safety risks of the work. The Interpretive Guideline on the officer duty under section 27 gives further detail.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.