HAZOP method, deviation analysis

The Hazard and Operability analysis was developed by Imperial Chemical Industry in 1963. It was established for chemical industries. Nowadays many companies use this method to enhance their project management. It is particularly well suited to systems that employ material and energy flows.

The main theory assumes that deviations forms are triggered by the operating design and bring about risk events. Guide words facilitate the identification of those deviations by a systematic list of deviation perspectives. Part of risk management’s process, this method optimizes resources and brings about financial benefits to the plant’s owner and operator. It highlights which control and safety systems are really needed to the plant. The quickest HAZOP’s recommendations are applied in the design process, the most are the benefits. Financial results are associated with the minimisation of the time related to the elaboration of the most efficient and safer device.

HAZOP aims to elaborate a safer, more reliable and more efficient plant by finding out how the system deviates from his first design intent, and generate risks for operators, equipment and processes. To accomplish it, all the deviations of a plant are systematically analysed by investigating its operating parameters. The strength is founded on the multidisciplinary team “brainstorming” at each step of this structured hazard analysis. Even though this study is often applied during the final design of the plant or the process before creating, it is also regularly updated during the operating stage of the plant.

History

HAZOP was initially thought for reviewing a new phenol plant design. The Heavy Organic Chemicals Division of the Imperial Chemical Industry (British and international company) conceived this method in 1963. At the beginning, it was based on a “critical examination” studying the alternatives of a system. Later, the method’s focus was altered in order to study system’s deviations after producing the first detailed design of the plant. The "operability studies" method was created.

In 1977, ICI published a guide of this method. It was officially named HAZOP. Since that date, the deviation analysis process has been applied in many projects from various types of company. Discussions and research have highlighted its usefulness in project management, but they have also unveiled some limits.