This paper introduces the procedures of developing a computer software-CASEHAT (Computer Aided Semiconductor Equipment Hazard Analysis Tool) that can facilitate different hazard analysis works for semiconductor manufacturing processes. The CASEHAT software is composed of three major parts: the material, the equipment, and the regulation database and they were connected through the 'correlated linkage' technique of the Microsoft Access and the VBA programming language. This innovative software not only generates ordinary HAZOP study (HAZard and OPerability study) results but also acts as an inquiry tool during usual conditions or in case of emergency. It is foreseeable that CASEHAT has great potential to be used in place of the current HAZOP procedure eventually. (C) 2003 Elsevier Science Ltd. All rights reserved.