5th Thailand International Chemical Engineering and Chemical Technology Asia Conference (TNChE Asia 2026), Thailand
The progression of an incident from a minor failure to a Major Accident Hazard (MAH) requires failure of one or more protection layers built in design which are commonly referred as Barriers. Barriers could be either preventive type which prevents the hazard (reduces likelihood) or mitigative type which minimises the impact of hazard (reduces consequence severity). Most common reason for MAH occurrence in Process Industry is due to the failure, degradation or absence of these critical barriers. Hence it is important to identify, monitor and maintain these critical barriers throughout the Project Lifecycle.
Management of these critical barriers include barrier identification (through PHA techniques such as HAZID, HAZOP, LOPA, QRA etc), assigning performance requirements (based on functionality, reliability, availability, independence etc) and having continuous maintenance/ testing programs to maintain barrier integrity.
One of the key steps for barrier identification is development of bow-tie diagrams which acts as visualisation tool that helps to show how a hazard can lead to an accident and how the barriers prevent or mitigate the consequences.
Hence in this presentation, the author provides introduction to development of bow-tie diagrams and the importance of barrier management with practical examples in terms of effective barrier identification and/ or maintenance-operating practices which otherwise can result in process safety incident.