A comparison study of qualitative and quantitative analysis techniques for the assessment of safety in industry

The primary function of safety systems is avoiding personal injuries or death and environmental pollution. Major problem is that, at this moment, there is no standardised method for the assessment for safety in the process industry. Many companies and institutes use qualitative techniques for safety analysis while other companies and institutes use quantitative techniques. The authors of this paper will compare different quantitative and qualitative techniques and will show that different analysis techniques show widely different results. It will also be shown that the qualitative techniques are highly dependent on human judgement while the quantitative techniques suffer from highly uncertain underlying data. Therefore in the second part of the paper a new quantitative technique will be presented that can be used for the assessment of safety, availability and triprate in the process industry. This technique can take into account effects of uncertain data and identify parameters that influence safety and/or availability dominantly. Finally the paper presents an example of the new technique applied to a practical system used in Dutch petrochemical industry.