This technique is derived from fault tree technique. This technique is used where there are massive plants and the normal life of that plant is 30 to 40 years. Risk Manager will involve where if questions, as were involved in fault trees. This study is a structured approach for a plant; structured approach means to break down the things into various steps. This study is also known as Nuts and Bolts study. It would be checked that whether the nuts and bolts of the machines are working properly or not, this requires much details, which can only be approached by a mechanical engineer.
This technique is most expensive and time consuming. Insurance also provides Machinery Breakdown Policy (MBP) or Comprehensive Machinery Insurance (CMI) to cover the losses which arise due to the risks associated with machinery.
Taking a full description of a process and questioning in a systematic manner every part of a process to check that whether there is any deviation from the intended plan is essential in the HAZOP process. Once identified, an analysis would be made to check the impact of such deviation, it will be seen that whether such deviation has negative affect on the production process or on the safe and sound working of a plant. Remedial actions will then be taken to eliminate any type of risk in the situation, if considered necessary.
Critical Analysis is done by the HAZOP team; they make an effort to discover the credible causes of deviation. Few deviations are common which could occur and cause losses but the team will concentrate to find out those risks which can not be commonly observed by a person. There are great chances that those potential failure and problems will be identified which had not previously been identified and known well.
The basic methodology of HAZOP study is that first of all the information is recorded then any deviation will be observed and analyzed, then the cause of that deviation will be analyzed and be searched out, the consequences from that deviation will then be listed, then safeguard techniques will be sorted out and at the last corrective actions will be taken.