THE LOOP IDENTIFICATION AND CLASSIFICATION ALGORITHMS FOR DIGRAPH-BASED SAFETY ANALYSIS

The task of identifying and classifying feedforward and feedback loops is an indispensable step in a digraph-based safety analysis. To addre ss the problems inherited from the traditional approach, i.e. manual i nspection, it is highly desirable to develop a generic software for au tomating the loop-searching process. Computer algorithms that facilita te its realization are presented in this paper. In particular, a simpl e search and delete strategy is proposed to identify every loop path c orresponding to a given ending node. Techniques for assembling these p aths to produce a comprehensive list of loops are also described in de tail. Finally, several practical examples are provided at the end of t his paper. The results show that the proposed algorithms are indeed qu ite reliable and efficient for the purpose intended. Copyright (C) 199 6 Elsevier Science Ltd