What is reasonably practicable is decided by weighing the likelihood of the hazard or risk, the degree of harm, knowledge of the hazard and ways to remove or reduce it, the availability and suitability of those ways, and cost including whether it is grossly disproportionate to the risk. For a designer, consideration is given to the prevailing design standards and the hazards and risks known when the structure was designed. Duties can be concurrent and overlapping: where several people share a duty each retains responsibility and discharges it to the extent of its capacity to influence and control the matter (WHS Act s 16). Designers may discharge their duty by consulting, cooperating and coordinating with those who control construction, for example by applying risk management to traditional designs and considering innovative approaches that are intrinsically safer, giving information on hazards in unconventional designs, advising how a structure might be built safely and working with construction safety experts. Where asked for information on an old building, the duty is limited to elements the designer specified, not changes made later by others.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.