How can we use the information provided by process safety performance indicators? Possibilities and limitations Hans Pasman * , William Rogers Mary Kay O’Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77840-3122, United States article info Article history: Received 13 March 2013 Received in revised form 10 June 2013 Accepted 10 June 2013 Keywords: Process safety Indicators Risk management Bayesian networks abstract To make further progress towards a safer industry, process safety performance indicators are indis- pensable. There are, however, some challenges involved with interpretation of indicator outcomes. By going too far in detail one loses overview, but in not noticing the important detail a false impression of safety may be obtained. Aggregation from a detailed level upward may give relief at this point, but what to do if indicator values do not improve any further? Is there a means to relate indicators to the plant’s risk level? The paper will show that when making use of the new technique of Bayesian networks for risk management, progress may be made. It seems possible to relate technical failure rates with risk factors acting over time duration and to take action before something breaks down. While originating in bad design, operation, maintenance, or neglect, these risk factors are influenced in the background by organizational, management, and human factors, which are subject to indicator monitoring. An example will be given of results one can expect when the dependencies are modeled in Bayesian network fashion. Current developments in other areas such as in aviation and offshore platform maintenance appear to be advancing in the same direction. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction All management planning, organizing, implementing, and con- trol with feedback, according to Deming’s Plan, do, check, and act cycle, require indicators on which to base decisions. The Working Group on Chemical Accidents of the OECD (Organization for Cooperation and Development with head office in Paris) issued in 2003 an interim Guidance on Safety Performance Indicators (OECD, 2003), which supported initiatives to establish indicators of, e.g., the Responsible CareÔ program of the American Chemical Council, ACC, and the chemical industry. This guidance document was fol- lowed in 2005 by a practical guide of the UK HSE (2006) and, following the Texas City explosion at the BP site, by CCPS publica- tions (CCPS, 2007a, 2007b, and 2010). In fact, the CCPS guidelines on the topic of process safety performance indicators result in close to 400 possible indicators measuring the effectiveness of 22 man- agement system elements. A major distinction is made between lagging and leading indicators, the former based on incidents, in- juries, and damages that surpass a certain critical threshold of seriousness, and thus can be counted, while the latter are factual data indicating to what extent one deviates from an ideal situation. This distinction is with respect to functioning of the safety man- agement system and the operational condition of the plant in which all agreed measures are taken or scheduled plans have been realized. The leading indicators have the character of how well one is prepared. The distinction is not sharply definable, e.g., near miss incidents, which give an important signal, can be regarded as lag but also as lead. Some years ago there was a vivid discussion on this aspect in Safety Science, stirred up by Hopkins (2009) with others commenting, e.g., Hudson (2009) who suggested a relation with bow-tie and risk. In January 2012 in Brussels, a two-day international conference dedicated to discussion of process safety performance indicators was organized by the European Process Safety Centre, EPSC, and the European Chemical Industry Council, CEFIC. This conference was very well attended, in particular by industry representatives, from the entire global community. Apart from the plenary opening and closing sessions with lectures and discussions, the more intensive deliberations were in four parallel working sessions on the following topics: I. ‘Implementing PSI: share your story so far’ II. ‘Broaden the basis e quick start for SMEs’ III. ‘Roadmap towards global PSI reporting’ IV. ‘Navigating ahead with leading indicators’ * Corresponding author. Tel.: þ1 31630551535. E-mail address: hjpasman@gmail.com (H. Pasman). Contents lists available at SciVerse ScienceDirect Journal of Loss Prevention in the Process Industries journal homepage: www.elsevier.com/locate/jlp 0950-4230/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jlp.2013.06.001 Journal of Loss Prevention in the Process Industries 30 (2014) 197e206