2 - Hazard and operability (hazop) studies applied to computer-controlled process plants

Abstract

This chapter focuses on the hazard identification aspect of safety assessment and discusses hazard and operability (HAZOP) studies applied to computer-controlled process plants. In the process industry, HAZOP is a long-established methodology used for identifying hazards in chemical plant design. Some attempts have been made to modify conventional HAZOP for computer-related systems. Modified versions of HAZOP are generally referred to as CHAZOP (computer HAZOP) or PES (programmable electronic systems) HAZOP in the literature. This chapter provides a brief description of the conventional HAZOP as used in the process industry and an overview of the different CHAZOP frameworks/guidelines suggested by engineers and researchers over the past few years. The overview shows that there is so far no agreed format on how CHAZOP should be done and that the different approaches were made ad hoc. The chapter presents a new CHAZOP methodology, which is systematically developed and based on incident analysis. The chapter discusses the strategy used to develop the methodology and illustrates the application of the methodology with examples.