Both of these tools are necessary in the process safety arena; however, they have very different and distinct roles in process safety management. In my career I found it best to perform the PHA first and based on the deviations identified in the PHA, we would write our SOPs to cover those deviations. And of course, every SOP gets written from a JSA/JHA. It works like this…
A PHA is a higher-level review of PROCESS DEVIATIONS and the consequences of these deviations. Of course, these deviations can be caused by human error, but during the PHA we are focused on process hazards and not so much on the traditional occupational hazards.
Let’s say the PHA team gets into a deviation/consequence that is going to require the facility to generate an SOP to instruct the operator on the steps to avoid or correct the deviation.