Periodic demands on layers of protection (i.e., prealarms, safety instrumented functions, relief devices, emergency response systems, etc.) are precursors to more serious incidents. The failure of one or more layers of protection is always part of an accident sequence. When they occur documenting these demands and the associated consequences in a way to facilitate analysis, provides a means to measure process safety management performance. Although process safety metrics are still in their adolescence, this article reviews experiences of development and implementation of a “Challenges to Safety Systems” process safety performance indicator. This article includes a discussion of automating significant portions of the data collection process based on the technical work documented by the CCPS PERD (Process Equipment Reliability Database) initiative. The article also recommends various metrics that can be calculated and describes how the initial foundation developed to support improved process safety can be leveraged to achieve other benefits, such as design improvements and improvements in the reliability, operation, and maintenance of the facility. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009

With the recently approved IEC 61511 and ANSI/ISA-84.00.01 standards, process industry companies are being challenged to determine the level of performance required from their safety instrumented functions (SIF) and to verify that the design, installation, operation, and maintenance employed is sufficient to ensure that the required performance is sustained until the SIF is decommissioned. As a practical matter, user companies must self-certify or user approve their SIF equipment, since they are responsible for the correct operation of the SIF in the operating environment, not just individual components as manufactured. To accomplish this, user companies need lifecycle assistance from equipment manufacturers, irrespective of hardware or software certification status related to IEC 61508. One of the best means to communicate the necessary information is via a safety manual for those involved in instrument system design installation and operation. IEC 61508 requires that equipment manufacturers provide a safety manual with any product claimed to comply with IEC 61508. Although required for product certification, it is the authors' current experience that quality and consistency in safety manuals is lacking. Part of this is due to IEC 61508 not providing a clear concise template with minimum requirements. The safety manual requirements are scattered throughout the rather complex standard. This article seeks to provide a user's perspective of what essential information is needed from equipment manufacturers to not only comply with IEC 61508, but also to provide enough information to the user of the product to allow the essential balance of reliability and safety in both SIF and instrumented protective function applications.

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data can he extracted in its desired form if only it can be found. I n contrast, this paperproposes data yarming, " and doscribes the "seeds" that are necessary to harvest the best possihkc> crop of reliability information. The CCPS Equipment Reliahi1it.v Database project provides valuable lessons on hou-to @rtn '* rather than merely "mine" data. The CCPS ulork processes for establishing failure modes, populations to track. went data to collect, and implementation are all reiiieuvd. Attention is given to knowing up front the data ohjectizu and the quality of information desired. Also, the tmatnient of equipment surveillance periods turns out to be a critical iwt-iable for data quantity and quality. Reasons for this and upproaches to take are discussed. It will be seen that the quulitv and continuity of derived information is much greater wheii the data sources can be ?armed" rather than "mined."