According to PHMSA, “A safety management system (SMS) is an organization-wide approach to managing safety risk through systematic procedures, practices, and policies. The Federal Aviation Administration (FAA) defines SMS as a “formal, top-down, organization-wide approach to managing safety risk and assuring the effectiveness of safety risk controls. It includes systematic procedures, practices, and policies for the management of safety risk.” [2] In the pipeline community, SMS is similarly described as a “systematic approach to managing safety, including the structures, policies, and procedures an organization uses to direct and control its activities.” [3]”
Follow this link to read the full advisory bulletin issued by PHMSA