Supporting plant disturbance analysis by dynamic causal digraphs and propagation look-up tables

This paper presents a method for the analysis of plant disturbances based on the combined monitoring of different but interrelated propagation carriers, specifically material flow-type and information flow-type carriers. The underlying notion of the proposed approach is that certain properties of plant assets, so-called propagation-related factors (PRFs), determine the behavior of disturbances being transported through the process by complex carriers´ combinations. Accordingly, the method relies on the systematic evaluation of PRFs and their specific influence on monitored carriers for the discovery of disturbance paths. Such a procedure is executed by a) the event-triggered generation of Dynamic Causal Digraphs (DCDGs), i.e. dynamic causal structures relating plant topology, flow directionality, propagation carriers, and plant asset properties, and b) the systematic consultation of a Propagation Look-Up Table containing PRF-based evaluation functions for the effect estimation of each node in a DCDG. As a result, the method allows for the ranking of discovered disturbance paths and the isolation of faulty plant zones, serving thereby as a basis for automated disturbance analysis and alarm grouping in process facilities.