摘要:AbstractThe paper gives an insight in how to deal with system complexity from a HAZOP study perspective. The research enlightens the importance of understanding system complexity in oil and gas industry and thereby gradually to change old-fashioned HAZOP industrial practice and improve safety performance in oil and gas industry. Methods and computer aided tools mentioned in the paper can improve HAZOP quality and efficiency with low manpower cost and support brainstorm section in HAZOP studies. The oil and gas industry can implement the method for HAZOP study on real plants to test its usefulness.