Human Error Probability Assessment for LNG Bunkering Based on Fuzzy Bayesian Network-CREAM Model

Hongjun Fan,Shantha Gamini Jayasinghe,Hossein Enshaei

doi:10.3390/jmse10030333

Abstract

Liquified natural gas (LNG) as a marine fuel has gained momentum as the maritime industry moves towards a sustainable future. Since unwanted LNG release may lead to severe consequences, performing quantitative risk assessment (QRA) for LNG bunkering operations has become mandatory according to some regulations. Human error is a main contributor to the risks, and the human error probabilities (HEPs) are essential for inclusion in a QRA. However, HEPs data are unavailable in the LNG bunkering industry so far. Therefore, this study attempts to infer HEPs through on-site safety philosophical factors (SPFs). The cognitive reliability and error analysis method (CREAM) was adopted as a basic model and modified to make it suitable for HEP assessment in LNG bunkering. Nine common performance condition (CPC) indicators were identified based on the fuzzy ranking of 23 SPF indicators (SPFIs). A Bayesian network (BN) was built to simulate the occurrence probabilities of different contextual control modes (COCOMs), and a conditional probability table (CPT) for the COCOM node with 19,683 possible combinations in the BN was developed according to the CREAM’s COCOM matrix. The prior probabilities of CPCs were evaluated using the fuzzy set theory (FST) based on data acquired from an online questionnaire survey. The results showed that the prior HEP for LNG bunkering is 0.009841. This value can be updated based on the re-evaluation of on-site SPFIs for a specific LNG bunkering project to capture the dynamics of HEP. The main innovation of this work is realizing the efficient quantification of HEP for LNG bunkering operations by using the proposed fuzzy BN-CREAM model.

Highlights

Accepted: 24 February 2022The number of liquified natural gas (LNG) fueled ships is rapidly growing due to LNG being considered as a viable transitional fuel in the maritime industry’s journey towards decarbonization [1–3]
The safety of LNG bunkering is a key issue of concern to the industry, because bunkering operations have a high likelihood of leakage [4]
Performing quantitative risk assessment (QRA) for LNG bunkering operations is either mandated or highly recommended for understanding and mitigating the potential risks according to the existing regulations and standards [5]

Summary

Introduction

Accepted: 24 February 2022The number of liquified natural gas (LNG) fueled ships is rapidly growing due to LNG being considered as a viable transitional fuel in the maritime industry’s journey towards decarbonization [1–3]. LNG is flammable and cryogenic, and unwanted release may lead to severe consequences. The safety of LNG bunkering is a key issue of concern to the industry, because bunkering operations have a high likelihood of leakage [4]. Performing quantitative risk assessment (QRA) for LNG bunkering operations is either mandated or highly recommended for understanding and mitigating the potential risks according to the existing regulations and standards [5]. Human error has become the main contributor to the risks in the maritime industry [6,7], where the combination of human and organizational errors during operations leads to about 65% of all catastrophic accidents [8]. As a result, when performing a QRA for LNG bunkering, the human error probabilities (HEPs) are essential inclusion. The definition of HEP is the opposite of that of the human reliability probability which refers to the probability that a person: (1) correctly performs a system-required activity and (2) performs no extraneous activity that can degrade the system [9]

Methods

Results

Discussion

Conclusion