Operator response to alarms is an important protection layer

摘要

Operator response to alarms is important layers of protection (LOP). When implemented with good design, engineering and maintenance practices, an alarm can help reduce the safety integrity level (SIL) of a safety instrumented function (SIF). The ISA84 standard covers the functional safety life cycle requirements of safety instrumented systems (SISs) and has been recognized by the US Occupational Safety and Hazard Administration (OSHA) as a generally accepted good engineering practice that can be used to comply with the process safety management (PSM) standard 29CFR1910.119 for SIS. In the initial phase of the safety life cycle, hazard and risk assessments identify the risks associated with the process. The risk is reduced to a tolerable level as defined by the corporate standard by implementing safety functions that act as LOP.