A renovation permanently removes a stair guardrail (engineered control) and leaves a traffic cone as the standing protection. What is the residual-risk problem?

Moving down the hierarchy—from engineered guarding to an administrative or warning device—generally increases residual risk unless the hazard itself has been reduced. Permanent substitution of cones for guardrails leaves fall or edge exposure poorly controlled. Changes that remove higher-order controls require formal reassessment and justification, not silent permanence.