System Safety Assessment process scope

Each PSM system can then be examined to determine what system modifications (if any) are needed to address the new issues. For example, the process hazard assessment system might be modified to include participation by industrial hygienists to identify potential sources of exposure. Some process safety management systems (e.g., process documentation) may require no modification to support a wider scope. 

Alternatively we may decide to create more specific claims, perhaps that the system performs at a level that is conducive to practical operation in a clinical environment and/or with a defined degree of availability. Whatever measure is selected it should be clear and concise and, most importantly, be capable of being demonstrated within the scope of the planned CRM assessment process. In other words it should be possible to draw lines of logical inference between each claim and the arguments set out in the body of the safety case. 

The lead auditor should prepare a list of questions pertinent to the scope of the audit. ISA-TR84.00.04-1 Annex D.4 Functional Safety Assessment provides example checklists that could be addressed during the audit. In addition, refer to the COPS book, Guidelines for Auditing Process Safety Management Systems," 2011. 

Most safety arguments eontain a set of assertions about processes and the eompe-tence of people with safety management responsibilities. The evidenee to support this type of argument comes fi om safety assessment/audit. A review takes place, independently of the day to day ineumbent, of the effectiveness and efficiency of the safety management system. It is an inherent feature of most systems that they are developed and improved within the scope of experience of a discrete set of professionals, and that it is easy for the working practices to have weaknesses which are difficult for the embedded staff to detect. 

System Conceptualisation, Representation and Scoping (System Analysis). This stage of the analysis is often omitted from safety literatnre and standards. This preparatoiy phase is necessaiy in order to provide a stmctured framework and systematic approach for the hazard identification, risk assessment, and for snpporting a holistic approach to the analysis. Some form of system description model, for example state transition model or sequence and collaboration diagrams, should be used as the basis for hazard identification, as the hazards resulting from each system interface, process or interaction can be elicited. The novel approach, developed as part of the research, to system conceptualisation in support of safety analysis, is discussed later in the book ... 

The MR also requires that before performing maintenance activities the licensee shall assess and manage the increase in risk that may result from the proposed maintenance activities. The scope of the assessment may be limited to those structures, systems, and components that a risk-informed evaluation process has shown to be significant to public health and safety. 

All safety activities refer to an item . An item in terms of ISO 26262 is defined as a system or array of systems to implement a function at the vehicle level, to which ISO 26262 is applied . The Item Definition marks the scope of the Safety Considerations on an overview level and is the starting point of all furflier safety activities. It is, in particular, a necessary preparation for the Hazard Analysis and Risk Assessment (HARA), because in order to identify malfunctions that may lead to scenarios that bear the risk of an accident (called hazards), the interfaces of the investigated system to its environment must be known, as well as the specified behavior at these interfaces. Deviations from this specified behavior constitute the item s failures, a subset of these constituting the hazardous failures. As explained above, CMSs are well-suited to be regarded as an item according to the definition in ISO 26262. So the Item Definition usually depicts the entire CMS with camera(s), processing unit(s) and display(s). 

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