Improved Strategies for the Maritime Industry to Target Vessels for Inspection and to Select Inspection Priority Areas

Sabine Knapp,Christiaan Heij

doi:10.3390/safety6020018

Abstract

Inspection authorities such as the Port State Control Memoranda of Understanding use different policies and targeting methods to select vessels for inspections and rely primarily on past inspection outcomes. One of the main goals of inspections is to improve the safety quality of vessels and to reduce the probability of future incidents. This study shows there is room for improvement in targeting vessels for inspections and in determining vessel-specific inspection priority areas (e.g., bridge management versus machinery related items). For the year 2018, sixty percent of vessels that experienced very serious or serious (VSS) incidents were not selected for inspection up to three months prior to the incident and forty percent of the vessels that were inspected still had incidents of which only four percent were detained. Furthermore, one can observe a very low correlation (−0.04) between the probabilities of detention and incidents (VSS) for the year 2018. The proposed approach treats detention and incident types as separate risk dimensions and evaluates seven targeting methods against random selection of vessels using empirical data for 2018. The analysis is based on three comprehensive data sets that cover the world fleet and shows potential gains (reduction of false negative events) of 14–27 percent compared to random selection. This can be further improved by adding eight inspection priority risk areas that help inspectors to focus inspections by providing insight in the individual risk profile of vessels. Policy makers can further customize the approach by classifying the risk of vessels into categories and by selecting inspection targets and benchmark samples. A small application example is provided to demonstrate feasibility of the proposed approach for policy makers and inspection authorities.

Highlights

This manuscript evaluates and challenges the status quo practice of the maritime industry to primarily use past Port State Control inspection outcomes to target future risky vessels for inspections as highlighted by Knapp [1]
One way to visualize how well the targeting methods perform compared to random selection of vessels is via ROC curves that plot the true positive rate (TPR)
The 817 incidents are manually checked to identify the first event of what is normally a chain of events

Summary

Introduction

This manuscript evaluates and challenges the status quo practice of the maritime industry to primarily use past Port State Control inspection outcomes to target future risky vessels for inspections as highlighted by Knapp [1]. The primary goal is to develop a method and possibly a practical tool that can be used by maritime administrations or integrated into their systems with the aim to enhance the detection of risky vessels and to reduce false negative events—in short to have a more proactive approach to inspection selection. The development of the method builds on work of Knapp and Franses [2], Heij et al [3] and Heij and Knapp [4] to select vessels for inspections with the highest benefit (reduction in risk) and to treat detention and incident risk as separate risk dimensions in order to reduce false negative events. A false negative event is an event where the targeting method classifies a vessel as low risk, but in reality, this vessel is a risky vessel. Ji et al [10] demonstrate that using incident data besides detention data improves the evaluation of registries and subsequent selection of ships for inspections

Methods

Results

Conclusion