(47ag) Enhanced Lessons Learned Approach from the Bscat Investigation Approach

A key aspect of process safety management is the effective transmission of lessons learned both around the organization and specifically to those who most need to know.  This often occurs poorly. 

Most investigation methods have been optimized for occupational accident investigation.  The BSCAT approach – Barrier-based SCAT – builds on an earlier root cause method, but integrates bow tie barrier structure into the investigation and provides a better focus for major accidents and their pre-cursor near-miss events.  All incidents can be converted into a bow tie sequence of barriers that were challenged and which either failed (and gave the incident) or some succeeded (terminating or mitigating the incident).

The BSCAT approach provides many benefits for lessons learned.  Its structure matches the API754 Tier 3 Process Safety Indicator as it records clearly challenges to safety barriers – and whether they worked or failed.  A feature of bow ties is that barriers are frequently repeated between different Threats and Outcomes and different bow tie Top Events.  Thus a barrier that was identified as failed or degraded from one investigation will warn that the same barrier used for other threats or appearing in different bow ties affecting other plants are also likely to be degraded.  Software that records all incidents into a database, can show barrier failures on all bow ties in which that barrier appears and thus automatically warn the barrier or bow tie owners throughout the orgnaization.  This does not require proactive communication from the plant where the incident occurred or from the Safety Department – as this often is incomplete.  

This paper also compares the application of BSCAT to other traditional root cause approaches and demonstrates the clarity of communication possible with the bow tie structure.  It has the added advantage that the focus on barrier failures tends to screen out “motherhood” recommendations that may be good practice but did not contribute to the incident.