Hazard awareness HAZOP

Therefore it is clear that the quality of information and the stage when it is available also influence PHA method selection. For the same reason it is not possible to carry out HAZOP for a plant at the conceptual stage. So, if quality data are not made available, then the team and the team leader have probably only two options they can either recommend to the authority to change the detailing desired from PHA or delay the selection and inform management. In the last example we discussed the lack of information. Similar things happen if the available data are not up to date. It is wrong to work with old data because such an exercise is futile. Therefore it is essential that the team leader is aware of this so that hazard evaluation performance is improved and not delayed. 

Doganavjargil, E. Fattori, M. 2008. Decision tree analysis as a tool to optimise patent current awareness bulletins. World Patent Information, 30,212-219. Dunjo, J., Fthenakis, V., Vilchez, J.A. Amaldos, J. 2010. Hazard and operability (HAZOP) analysis. A literature review. Journal of Hazardous Materials, 173, 19-32. 

This paper is concerned chiefly with Hazard Analysis and Risk Assessment when PES are used to carry out critical safety functions and the use to these ends of a modified Hazard and Operability (HAZOP) methodology. In order to put the HAZOP in perspective, some other major factors, influences and definitions will be addressed in the first part of the paper, beginning with the concept of Safety Lifecycle, followed by a short discussion of software risks, some case histories and a description of the development of the HAZOP approach to Hazard Analysis, including the increasing awareness of the signifrcance of human error. 

Used in conjunction with ISA-TR84.00.04-2005 Part 1, the example set forth in this technical report is provided to illustrate howto apply ANSI/ISA-84.00.01-2004 Parts 1-3 (lEC 61511 Mod). It is intended to demonstrate one method to meet the requirements of the standards. The reader should be aware that ANSI/ISA-84.00.01-2004 Parts 1-3 (lEC 61511 Mod) is performance based, and that many approaches can be used to achieve compliance. Some of the methods applied in this example include what-if and HAZOP techniques for hazard and risk analysis, LOPA for allocation of safety functions to protection layers, fault tree analysis for SIL verification, and ladder logic to document the application software requirements. Other techniques and tools could be utilized at each of these steps in the safety lifecycle to meet the requirements of the standards. 

---