Top management's formal commitment is critical: without it individuals have no mandate and sustainable procurement stays ad hoc; sustainability should be built into the procurement function at its most senior, strategic level, into the procurement policy (intentions, objectives, values) and the procurement strategy (how they are delivered, with objectives, targets and a work plan), both linked with the organization's policies, the goal being to embed sustainability in existing documents.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.