Integrated dynamic decision analysis: A method for PSA in dynamic process system

One of the important issues still under investigation in order to increase the confidence in the results obtained in the PSA of technological systems is the physical modelling of the process. Integrated Dynamic Decision Analysis provides a full representation of the plant states, as well as all the possible occurrences patterns, expressed in a set of mutually self-excluding sequences. The availability of the full set of alternatives allows the complete spectrum of possible probability-consequence conditions to be used as a basis for decisions in risk reduction. Furthermore it is possible to interface with the logicprobabilistic model a process simulator, in order to assess the status of each relevant process variable with reference to the failure sequence identified, allowing the mutual interactions of the hardware components and the physical evolution of the plant to be taken into account. This approach is here described through a simple case study taken from literature.