Application of Layer of Protection Analysis (LOPA) in Verification of Safety Integrity Level of Instrumented System

• Main Author: Mahamad Anuar, Mustafa Kamal Helmi
• Format: Final Year Project
• Language: English
• Published: UNIVERSITI TEKNOLOGI PETRONAS 2012
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/6137/1/Dissertation%20Mustafa%202012%20%2812096%29.pdf; http://utpedia.utp.edu.my/6137/
• Institution: Universiti Teknologi Petronas

Incomplete process hazard analysis (PHA) and poor knowledge management have been two major reasons that have caused numerous lamentable disasters in the chemical process industry. To improve the safety integrity of a process system, all risk should be reduced to a tolerable limit. One way of doing it is by adding layers of protection which include inherent safer design, basic process control system (BPCS), alarms, SIS, physical protection, and emergency response procedure. These layers however, are cost to the process industry in term of implementing it as well as maintaining the quality of the layers. Therefore, understanding the required safety integrity level (SIL) of a process is essential in order to meet the tolerable risk target as well as to optimise the cost of a safety system. Meanwhile, layer of protection analysis (LOPA) is a simplified approach to verify SIL of a process system. Nevertheless, the method is relatively new and various modifications have take place by different entities. Therefore, there is a need to maintain the consistency of the LOPA result by adhering to a standard procedure and practise as well as clear direction provided by Centre of Chemical Process Safety (CCPS). This can be done easier by developing a framework for LOPA analyst to follows as well as tailored to the company background and history.