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I have noticed that with the multitude of process calculation spreadsheets on this site and on internet, there are little or no process safety spreadsheets, unless you want to pay large sums of money for a full-scale HAZOP program. I do not doubt that those are needed when you are starting a major process or working with something expressly hazardous. However, when making a change through an MOC where there is little chance of injury or environmental hazards, while HAZOP might not be necessary, some sort of safety review should be done. In the event that a typical Job Safety Analysis would not be enough, and a full HAZOP would be overkill, you need a What-if analysis. I've attached a macro-enabled Excel spreadsheet that should guide someone who has a familiarity with the what-if process through a successful study. Please use it as you want, feel free to modify it for your or your company's needs. The point of this is to push industry as a whole to be safer, and get away from not doing a sit-down hazard study simply because you don't have a license for a HAZOP program.

Attached Files

•  whatif PHA.xlsm   36.67KB   147 downloads

Edited by Stephen80, 27 March 2012 - 11:20 AM.

[Nick Howard]

Stephen,
I've downloaded this and it seems a very good idea, so thanks. I'm currently leading a team of Technical Safety Engineers on a North Sea FPSO project. Some of the work involves changes to process systems, some are simply pipe spool or instrument change outs (for more robust types).
You're right in that sometimes a full HAZOP isn't required and I think the latter examples above are ideal for what-if analysis.
I have been undertaking Design Safety Reviews, which use mainly HAZID guidewords but they seem to work well. However, I also use a HSE questionnaire to identify residual risks.

I think the key is good attention to detail throughout the design process, and I highly recommend a Designer's Risk Assessment. I also think that sometimes safety in design is left down to the hazard studies to identify any problems!

Regards,
Nick