Chemical Safety Board Report: A Wicked Problem
The Limits of PHAs, LOPA and SIS
Yesterday we provided some initial thoughts regarding the CSB report and the fatal accident at the BP-Husky refinery.
The following statement from page 67 of the report caught my eye,
The hierarchy of controls and layer of protection analysis (LOPA) methodologies are used to determine the adequacy of available safeguards and select prevention and mitigation strategies when the current safeguards are deemed insufficient. Prevention and mitigation measures include but are not limited to instrumentation, process controls, and safety instrumented systems (SISs).
Although the BP Toledo Refinery conducted PHAs to analyze liquid overflow events and LOPAs to determine the effectiveness of identified safeguards, the refinery’s safeguards were not effective in preventing liquid naphtha from overflowing . . .
One conclusion that could be drawn from this statement is that the traditional analytical methods ― PHAs, LOPA and SIS ― did not identify the potential for this event, and therefore their implementation needs to be improved.
But another interpretation could be that we need to consider new ways of thinking. Maybe these established techniques are reaching the limit of their usefulness. If so, new approaches, such as Wicked Problem Solving, are called for.
