Plan-Do-Check-Act (PDCA) provides a framework for continually improving an OHSMS in accordance with ISO 45001.

A-Hazard identification, B-Internal Communication, C-Management review, D-Incidents

ISO 45001 structures the OHSMS around the Plan-Do-Check-Act model. Plan includes identifying hazards, assessing OH and S risks and opportunities, determining requirements, and establishing objectives; therefore, Hazard identification belongs to Plan. Do concerns implementation and operation of the management system, including support processes such as communication, making Internal Communication the correct placement. Check covers monitoring, measurement, internal auditing and management review, so Management review belongs to Check. Act addresses improvement following performance evaluation, including responding to incidents, nonconformities and corrective-action requirements; therefore, Incidents belongs to Act. The mapping reflects the ISO 45001 clause architecture: planning in Clause 6, support/operation in Clauses 7–8, performance evaluation in Clause 9, and improvement in Clause 10.