Process safety, leading and lagging metrics

To provide guidelines and examples of effective practices for the development and use of process safety leading and lagging metrics ... 

Center for Chemical Process Safety, Guidelines for Process Safety in Batch Reaction Systems, American Institute of Chemical Engineers, New York, 1999 Center for Chemical Process Safety, Process Safety Leading and Lagging Metrics, American Institute of Chemical Engineers, New York, 2007 Reason, J., The contribution of latent human failures to the breakdown of complex systems. Philosophical Transactions of the Royal Society (London), series B. 327 475-84(1990)... 

The ultimate goal of the process safety system is to prevent process safety incidents. The Center for Chemical Process Safety s Process Safety Leading and Lagging Metrics Report (CCPS, 2007b) defines a consensus from several chemical and allied processing industries for definitions of process safety incidents and process safety near misses. If an organization adopts these definitions, a... 

Common process safety metrics, such as the number of process safety incidents, can provide a basis for such comparisons among facilities within an organization, among different companies within an industry, and even among different industries. The major goal of CCPS s Process Safety Leading and Lagging Metrics is to create such common definitions. 

Center for Chemieal Proeess Safety, Process Safety Leading and Lagging Metrics, American Institute of Chemical Engineers, New York, 2007... 

As discussed earlier in the book, common metrics are necessary for companies to compare their performance with other companies and overall industry performance. Consensus process safety metrics are only beginning to be adopted within the processing industries. Consensus process safety metrics are being developed, such as those recommended in the CCPS publication Process Safety Leading and Lagging Metrics. Pressure from within the industries and from outside stakeholders will encourage the broader acceptance of current consensus metrics as well as the development of more such metrics. Such metrics will be used not only by companies and industries, but especially by outside parties to evaluate industry-wide performance or the performance of individual companies against the industry as a whole. 

In 2008 the Center for Chemical Process Safety (CCPS) published Process Safety Leading and Lagging Metrics—You Don t Improve What You Don t Measure. 

The immediately preceding quotation is the definition of a leading indicator in the Process Safety Leading and Lagging Metrics paper. 

Process safety leading and lagging metrics Center for Chemical Process Safety 2009 www.aiche.org/ccps... 

Process safety—and the metrics to identify and track it—can be incorporated into a company s overall sustainability program. Adoption of improved process safety leading and lagging indicators that document improving process safety performance will be important in maintaining the organization s license to operate broadly as well as in a specific location. 

This interest led to the CCPS Technical Steering Committee authorizing the creation of a project committee to develop a book of guidelines for the development and use of leading and lagging process safety metrics. To achieve broader industry acceptance, CCPS invited representatives from many chemical and petroleum companies, trade associations, labor groups, regulators, and academics involved in the field of process safety, as well as other key stakeholders or subject mater experts to participate in this committee s activities. 

One documented method uses process safety barriers identification for metrics selection. This concept uses a combination of lagging and leading indicators associated with process safety barriers and incident escalation controls to evaluate the process safety system performance. The basis for this method is documented in the U.K. Health and Safety Executive (HSE) publication HSG254 and illustrated by Figures 4.1-4.3. The strength of this technique arises from using the combination of indicators that provides multiple perspectives for judging the surety of a barrier or escalation control. For example, this basic concept was adopted and modified by BP to focus upon three information sources to assess key control barriers as summarized below ... 

Chapter 3—Process Safety Management Metrics commonly used in process safety management systems including leading, lagging, and near miss and activity and outcome, external and internal metrics as well as characteristics of successful metrics... 

The process safety pyramid described in Figure 1.2 provides a useful concept for categorizing metrics by severity. Lagging, leading, and near-miss metrics are associated with the different levels of the safety pyramid. Figure 3.1 illustrates how each of these four areas fit into that categorization. ... 

Near-miss metrics include actual process safety incidents that do not meet the threshold defining a lagging metric as well as system failures that could have, but did not, lead to an incident such as an instrumentation failure or vessel corrosion. Near misses are often less obvious than accidents and are defined as having little if any immediate impact on individuals, processes, or the environment. Despite their limited impact, near misses provide insight into accidents that could happen. 

Three types of process safety performance metrics are described in the document and the text on their selection and application is extensive. Reference is made to lagging metrics leading metrics, and near miss and other internal lagging metrics. Note that near misses are a metric separate from lagging indicators. This is the only publication found that makes that disfinction. As will be seen, there is a purpose for doing so in the CCPS document. The metrics pertain only to chemical process incidents and near misses, to the exclusion of types of incidents that are not process related. 

Risk assessment A formal, structured, and methodical safety risk assessment process was developed and embedded on the factory floor. The safety risk assessment process was designed to be proactive and identify leading safety risk indicators that would point to new safety problems, not just based on past history (lagging safety indicators). Results were then used to create leading safety risk indicators— metrics that will identify where I will have future safety problems. 

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