For rail safety purposes a change is anything able to alter an existing risk or introduce a new hazard. Changes to management, systems, processes or assets are all in scope, and any change that could affect the safety management system or the conditions of accreditation should be treated as a change: rolling stock, infrastructure, equipment and facilities; technology such as signalling or IT; the work environment; work practices, policies and procedures; services and operational areas; organisational structure, roles and relationships with contractors, suppliers and agencies; business strategy; interfaces with other rail organisations; and the regulatory environment. Because one change can touch several of these and the interfaces between them, the operator shall take a systemic view so that effects on every element and interface across the life cycle are identified, assessed and controlled.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.