Double Jeopardy in HAZOP study

[bkay]

The BP Texas refinery incident highlights the need to question the assumption in HAZOP study that two failures will not occur at the same time. I personally feel that the HAZOP teams often overlook the human issues and assume only one failure. Comments are welcome!

[Gasflo]

Well you need to assume that the technicians in contact with the equipment are competent enough to operate it. If this assumption is flaw then there is a big problem with processes and procedures on that particular plant. What about maintenance philosophy, frequencies and scope. You need to draw a line on the sand and relay on other activities that are part of a normal and safe operation of equipment.