Hazard identification based on plant functional modelling

A major objective of the present work is to provide means for representing a process plant as a socio-technical system, so as to allow hazard identification at a high level in order to identify critical areas and the need for further analysis using existing methods. First, a plant functional model is prepared where a set of plant functions link together hardware, software, operations, work organisation and other safety related aspects of the plant. The basic principle is that any aspect of the plant can be represented by an object based upon an Intent (or goal); associated with each Intent are Methods, by which the Intent is realized, and Constraints, which limit the Intent. The Methods and Constraints can themselves be treated as objects and decomposed into lower-level Intents so giving rise to a hierarchical, object-oriented structure. The plant level hazard identification is carried out on the functional model using the Concept Hazard Analysis method. In this, users will be supported by checklists and keywords and the preparation of the plant functional model and the performance of the hazard identification can be carried out manually or with computer support. Note that while this paper refers to process plant, the method and conclusions have been shown to be applicable to systems in general. (C) 1997 Elsevier Science Limited.