(54ag) Hazid, HAZOP and QRA: Three Key Aspects for an Effective Sil Assessment Studies

Today Process Industry carry out different risk assessment studies to evaluate effective requirement for operational and maintenance efficiency by understanding the risk. However, often process industries fail to understand to interlink different risk assessment studies and get an effective result. Any process industry mainly carry out HAZID, HAZOP, QRA and SIL study to understand the risk profile of the facility in terms of impact on Personnel, Environment, Occupational Health and Reputation. All these studies follow a loop/cycle in which they get updated as progress of any project.

Any safety instrumented function plays a major role in a process industry. Its accuracy, reliability, maintainability and cost effectiveness depends on the accuracy of HAZID, HAZOP and QRA studies carried out. HAZID is the first study which is carried out in any process industry. It mainly identifies the overall external risk factors for green field with respect to effect from Natural Calamity, Surrounding facility, project implementation issues. These inputs are very much essentials which gives pavement for an effective HAZOP and QRA studies. QRA carried out identifies the consequence modelling for the process based on different leak sizes from flanges, instrument tapings and prevailing weather condition. This input is very much essential for carrying HAZOP studies where it identifies various hazards and operability consequences which relates to impact on personnel, environment, occupational health and reputation of the facility. Having done HAZOP, QRA again gets updated based on any additional instrumentation/hardware addition. HAZOP plays a most important input to SIL Assessment study to evaluate the safety instrumented function for most credible consequence, identifying the tolerable frequency gap to be fulfilled by the safety instrumented function.

This paper summarises how a well performed HAZID, HAZOP, QRA integrates with Safety Instrumented Function assessment and can be cost effective.