Human Factors for LOPA

The basic methodology in Layer of Protection Analysis (LOPA) is well defined. One of the more attractive features of this method is the inclusion of human factors issues for both the initiating event and as safeguards or IPLs (Independent Protection Layers). The task of the LOPA analyst is to understand the role of humans in the scenario (either initiators or IPLs) and to assign a defendable value to the human factor. This session seeks papers that can present human factors tools that have been successfully applied to actual LOPA studies. Where several human factors tools have been used a comparison of these methods for their use in LOPA should be stressed. One area of comparison might be the ease of use in verifying an order of magnitude value for a human error initiator or human factor IPL in a LOPA study. Also actual use of human factors analysis as applied to the verification of standard IPLs such as the need for a block valve under a relief valve will be considered.