Ensure your “units of measure” are CONSISTENT
If the sight-glass for LEVEL is in Inches = the SOP needs to state INCHES
If the TEMPERATURE Gauge/Panel reading is in Degrees C = the SOP needs to be in Degrees C
If the PRESSURE Gauge/Panel reading is in PSIG = the SOP needs to be in PSIG
We just assisted a client in understanding a recent event, and the organization found the event was caused by “operator error”. In a deeper dive, we found how/why the operator made the error.
The instruments in the field did not match the units of measure in the SOP, nor did they match the DCS/HMI readings. This new operator was forced to convert the units of measure, and he made a slight mistake, and that “slight miscalculation” led to a LOPC event.
This is a baseline HF failure in the organization. Yes, the operator made an error, but he/she should never have been put in that situation to make such an error. This was NOT an “Active Failure”, this was a “Latent Organizational Failure”. The SOP he/she was following had been annually certified for 13 years, and not once did any operator speak up that the units of measure in the SOP differed from those used on the equipment and control panels.