Safety critical element

Conducting operational risk assessments where the operations need to be continued with any degraded safety critical element (SCE) in place... 

Safety critical elements are any part of the installation, plant, or computer program whose failure will either cause or contribute to a major accident, or the purpose of which is to prevent or limit the effect of a major accident. The process of identification of safety critical elements on an asset generally follows the following steps ... 

Those performance standards associated with establishing initial suitability may be different from those used to assess ongoing suitability throughout the operational life of the safety-critical element. Some companies prefer to merge both requirements in to one (i.e., initial and ongoing suitability), or some prefer to develop separate performance standards. Regardless of the approach, the basic objective is to ensure that the requirements set in the performance standards assure that the safety-critical element can fulfill its function. 

Currently in the United Kingdom, the HSE is deemed to have a sophisticated inspection regime with independent third-party verification system for well design and safety-critical elements offshore. Interestingly, these verifications are conducted not by another governmental agency but by entities in the industry such as... 

Safety critical elements in the MHR would require independent verification. 

Although a Safety Case can and should cover aU aspects of safety (occupational, process, and technical, as described in Chapter 1) the focus tends to be on identifying and avoiding what are known as Major Accident Events (MAE), i.e., catastrophic events such as fires, explosions, and the release of toxic chemicals. Associated with Major Accident Events are Safety Critical Elements and Performance Standards. 

Associated with each MAE is one or more Safety Critical Elements (SCEs) which prevent, control, or mitigate the MAE. 

Essential for the integrity of any installation are the safety-critical elements (SCEs). These are the parts of an installation and its plant (including computer programmes) whose purpose is to prevent, control or mitigate major accident hazards (MAHs) and the failure of which could cause or contribute substantially to a major accident (NOPSA, 2009). 

Thereafter the designers have to identify the necessary barriers and controls for the identified hazards and safety functional requirements. (A barrier or a control, which prevents a hazard is called a safety critical element (SCE).) The barriers and controls will typically consist of a mixture of mechanical barriers, instrumentation and control (I C) systems, and fire-fighting systems, combined with administrative controls. Functional requirement specifications for all the necessary SCEs are then included in the overall design specification. 

Identify barriers and controls (safety critical elements SCEs) Assess potential consequences of accidents... 

The 2007 edition reflects the most recent experiences of the industry, and its current and best practice, and is more user-friendly in order to encourage its wider use. The Guidelines are intended to provide good practice in the identiflcation, verification, and management of Safety Critical Elements, and will assist in compliance with the Safety Case Regulation and the Design and Construction Regulations for the UK offshore oil and gas industry. 

Energy Institute, 2007. Guidehnes for the Management of Safety Critical Elements. 

On many occasions supervision is a safety critical element contained in a safe system of work (SSOW). When it fails it may result in dire consequences such as personal and financial losses. 

Dhar, R. 2011. Performance Standards For Safety Critical Elements— Are We Doing Enough In SPE European Health Safety and Environmental Conference in Oil and Gas Exploration and Production. Society of Petroleum Engineers. 

Brewerton, R.W. et al.. Experience in the application of the goal setting regime and risk-based design of safety critical elements in the oil and gas industry. Proceedings of the ASME 32nd International Conference on Ocean, Offshore, and Arctic Engineering, 2013, pp. 52-57. 

After several years experience of employing the safety case approach in the UK offshore industry, the safety case regulations were amended in 1996 to include verification of safety-critical elements and the offshore installations and wells (design and constmction, etc.) regulations 1996 (DCR-1996) were introduced to deal with various stages of the life cycle of the installation (HSE (1996b)). From the earliest stages of the life cycle of the installation the... 

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