Showing posts with label LOPA. Show all posts
Showing posts with label LOPA. Show all posts

Sunday, February 23, 2014

Human Factors in HAZOP & other risk assessment techniques

How important are human factors when carrying out risk assessment studies such as HAZOP, LOPA and other techniques? Very much important it turns out, although until now most practitioners did not include this factor in their risk assessment studies. But of course we know that accidents can and do happen due to human error. Is there a policy guideline for this in place? Yes, it turns out that there is, in fact it was released a long time ago.
The UK Health and Safety Executive reportedly is mulling to include a "human" factor in risk assessment of major hazard facilities (COMAH). They have released a policy roadmap that details this here.
For example if the Risk assessmnet of a major hazard facility shows that it is essential to carry out some maintenance tasks regularly to reduce the risks, then a human factors analysis should be done to find out if
a) whether the task itself could be skipped?
b) whether any alarms can be raised if this is skipped due to error, negligence or simply laziness?
c) whether an incompetent performance of this task could result in an accident?
Very valid questions and a long way to go to analyze all the myriad things that humans can and many times actually do wrong!
So in your next HAZOP review one of the deviations should be "operator did not perform the task at all OR he did not perform the task correctly". This condition has not been included in any HAZOP formats or software to the best of our knowledge but should be and will, in the near future.
If you would like to know more about this aspect, you can check out the Abhisam course here.

Tuesday, September 24, 2013

PHA-Process Hazard Analysis

Today, we will examine in brief what is referred to in industry parlance as PHA or Process Hazard Analysis. PHA refers to any technique that is used to identify hazards that may exist in any industrial, manufacturing or any such similar activity. More specifically it refers to the hazards that are to be identified in the process industry. As you know the "process industry" is a generic term that covers a wide range of industries such as chemicals, oil and gas, power generation, mining and the like. These industries have several hazards present due to the nature of their operations and they need to be identified, reduced to a safe enough level to minimize the risk of accidents and thus mitigate them. PHA thus refers to any technique that can reliably do so. There are several PHA techniques that are used in the process industry and they are HAZOP (Hazard and Operability Study), What-if analysis, HAZID, LOPA (Layer of Protection analysis) to name a few. Out of these HAZOP and LOPA are growing in popularity worldwide.LOPA as a PHA technique is also used as a SIL determination technique. SIL is an acronym for Safety Integrity Level and we will cover that in a separate post.