An Integrated Safety for Business Analyses of Process Plants

Abstract

1 Abstract In this study a safety assessment technique is described, in which the contributions of a number of technical and organisational aspects of safety can be compared and quantified. Results can be used for input in recommendations regarding investment decisions, and for development of safety performance indicators that could be used by management alongside other (more traditional) business performance indicators. The technique revolves around the identification of incident scenarios in a LOPA type approach. In LOPA (Layer of Protection Analysis) severity and likelihood of these scenarios are assessed in a semi-quantitative way. Scenarios can be related to the (chemical) process, or the integrity of installations and components. Safety studies addressing non-technical, organisational aspects are bundled in a Safety Quality Factor, which is used to adjust scenario frequencies. A safety rating can be calculated from the frequency of occurrence of the scenarios. A comparison of the safety rating with the target values set for the scenario may yield a safety gap. Safety measures can then be identified and their effect on the safety rating can be assessed. If financial implications of these measures are also calculated the cost-effectiveness can be determined. This may help deciding which measures should be taken. The SBA technique is being pilot tested on a real chemical site in the Netherlands. First results are shown. 2 Introduction On most locations where chemical compounds are processed or stored safety is of more than average importance. Safety assurance usually requires a multitude of assessments applied during various stages of plant life, addressing different aspects of safety (worker's safety, process safety, environmental safety) through multiple levels of the organisation (operational, supervisory and strategic). Techniques may be qualitative or quantitative in nature and may be aimed at technical or more organisational and managerial aspects of safety. It is usually difficult, if at all possible, to combine the results of the various studies a coherent safety assessment, allowing the evaluation of the relative importance of one measure compared to another. This may hamper investment decisions, in which choices need to be made. In 2001 TNO started a project in which the know-how of a number of TNO institutes was combined and which was aimed at integrating technical safety analyses with an organisational safety approach, with the ultimate goal to enable companies to take balanced decisions regarding (safety) investments. Here the methodology is explained and results of pilot study are shown.