RANDAP: An integrated framework for reliability analysis of detailed action plans of combined automatic-operator emergency response taking into account control room operator errors

• Detailed Action Plans (or DAP's) are designed as a series of instructions to be performed in emergency response
• Our research is on how correctly the automatic and operator instructions can actually be performed in emergency conditions.
• A framework is proposed and evaluated for analyzing and improving the ‘reliability’ of a given DAP.
• The framework consists of appropriate models for human reliability and equipment reliability.
• A case study shows that the reliability of a DAP can be surprisingly low, but can be improved using the framework.

Automatic process control and control room operators supervision/intervention in an emergency are of critical importance in major hazard industries. These combined operator and automatic actions are defined in Detailed Action Plans (DAP). A framework has been proposed for analyzing the reliability, and hence the likelihood of success, of DAPs. The Reliability Block Diagram technique is utilized for modeling the reliability of integrated automatic-operator emergency actions. The focus is on incorporating operator's operational and cognitive errors in the process/equipment reliability analysis. For this purpose, the human reliability analysis method SPAR-H is utilized. The proposed framework was used for analyzing emergency response DAPs of a real process plant in order to check and improve its applicability. It is argued that the presented framework facilitates the DAP assessment process by performing Task Analysis, modeling the detailed tasks as well as reliability analysis, thereby uncovering the shortcomings of the designed DAPs. Besides, it provides a very effective, transparent tool with insight into improvement areas and directions for improving the reliability of DAPs.