Bow-tie Method Research Articles

The Suez Canal Incident: Learning from Failure by Using Reliability and Maintenance Techniques

The purpose of this paper is to investigate the Suez Canal incident by formulating a hybrid model, inspired by maintenance and reliability techniques, that can enable the process of learning from failures. The hybrid model uses a fault tree analysis (FTA), reliability block diagram (RBD), cut set analysis (CSA), and the bowtie method (BTM). The formulated techniques show the synergy between the techniques and how they can be incorporated in order to provide a better understanding of the incident and extract the lessons learned that can prevent a reoccurrence of such an incident. The need for a such hybrid model is essential nowadays since incidents and disasters are becoming more complex, hence a deep analytic technique is required to cover all reliability factors. It can be argued that there is no perfection in using only one technique to address all the reliability aspects, and it is vital to integrate more than one technique, with its particular advantage, in order to have a clear, focused and comprehensive understanding of the area of concern. In addition, it is essential to derive from that level of analysis lessons that can help to improve the overall system reliability and prevent future undesired events.

Dynamic industrial risks assessment for enhanced safety in the oil and gas industry: a methodological innovations and applications

In recent years, continued and accelerated growth in the oil and gas sector has significantly contributed to catastrophic accidents in various regions of Algeria, especially those with high population densities. Therefore, assessing the risks associated with these industries is crucial to prevent such disasters. This study introduces a methodology integrating several Quantitative Risk Assessment techniques, such as Failure Modes and Effects Analysis, Fault Tree Analysis, Event Tree Analysis, and the Bow-Tie method, coupled with simulation tools (ALOHA and FLUENT). This integration created a Dynamic Industrial Risk Assessment Methodology (DIRAM), a comprehensive approach to assessing industrial risk consequences in the oil and gas industries. The study demonstrates DIRAM's effectiveness in understanding the dynamics of catastrophic events. It provides a visual representation of CO2 plume and heat dispersion after a Boiling Liquid Expanding Vapor Explosion (BLEVE), emphasising the importance of spatial-temporal awareness in risk assessment and emergency response. DIRAM offers a valuable basis for preventing and managing potential risks and reinforcing safety measures at hydrocarbon plants.

Risk analysis of petroleum storage tank based on uncertain data incorporated into mapped Bow-tie to Bayesian network

The petroleum industry has an important impact on the environment, which is why risk analysis for a petroleum storage tank is required in the process industry. However, conducting an exhaustive study is frequently complicated due to the incomplete data based on historical system information, feedback, or test results. The main goal of this study is to develop an innovative framework that integrates the Bow-tie method with MIMAH (Methodology for the Identification of Major Accident Hazards). This approach specifically aims to identify the most critical accident scenario and comprehensively list all realistic causes (basic events) associated with petroleum storage tanks. Acquiring historical data on basic events poses challenges due to the lack, insufficiency, and imprecision of failure data. To address this obstacle and predict the system’s evolution, a combination of established methods for handling uncertainty and multi-criteria decision-making has been proposed. This combination incorporates a modified Fuzzy Analytical Hierarchy Process with Chang’s Extent Analysis Method (FAHP-EAM), fuzzy set theory, and expert elicitation, contributing to an extensive approach for managing uncertainty and making informed decisions in the absence of comprehensive historical data. Furthermore, the Bow-tie model is converted into a dynamic Bayesian network to improve risk analysis by integrating probabilistic reasoning and capturing the dynamic interactions among multiple risk factors. This integrated approach is validated on real scenarios. The utilization of dynamic Bayesian networks further facilitates the suggestion of scenarios to assess the contribution of basic events to the critical event and evaluate the resulting environmental impacts. Finally, the prediction of threat zones for various hazardous effects, such as toxicity, thermal radiation, and overpressure linked to chemical releases following the occurrence of the critical event, is carried out. The risk analysis outcomes from this study offer valuable data for assessment, enabling managers to improve the quality of risk management and formulate effective risk mitigation strategies.

Eliminating the Occurrence and Consequences of Toxic Release in Petrochemical Industry through Intervention of Safety Engineering Tools

The aim in this project is to analyze the risk associated with different toxic releases which is occurring in the chemical industry and to minimize its release using safety engineering tool in order to make the working environment safer. The sector of petrochemical industries is very important and have specific place in our country. Since the beginning, the Indian petrochemical industry has shown an enviable growth rate. This industry also contributes largely to the economy of the country and the growth and development of manufacturing industry as well. Petrochemical industry has a high risk of toxic release. The main causes of accidents are the chemical splashes which can occur for instance when a pipe or a tank burst under pressure or during disassembling operations of pipes or valves. There are a number of ways of toxic release at each and every process of petrochemical industry. We have identified the way in each process of the petrochemical industry. We have taken H2S as toxic gas and performed analysis, with the help of Bowtie methodology. Result obtained by evaluating various processes in petrochemical industry, we found that H2S can be released in three major sections i.e. transportation, storage and processing units. Using bowtie method, resolutions has been done to decrease or eliminate the possibilities of leakage of H2S

An integrative risk assessment approach to enhancing patient safety in Continuous Renal Replacement Therapy (CRRT)

Continuous Renal Replacement Therapy (CRRT) serves as an intervention strategy for the management of acute kidney injury (AKI) in critically ill patients. However, owing to its complex nature and the potential for complications, the implementation of CRRT demands continuous monitoring to prevent patient safety risks. This study aims to identify and validate prevalent risks linked to CRRT within a real-world clinical setting, intending to propose preventive measures grounded in expert insights. To systematically categorize and visually depict the risks, their consequences, preventive measures, and recovery controls, our study employed the Bowtie method in conjunction with the Systems Engineering Initiative for Patient Safety (SEIPS) model. In addition to considering patient-related factors that exhibit variability among critically ill individuals, our key findings showed that the most influential risks impacting the effective delivery of CRRT are incidents of clotted filters, bleeding risks arising from the necessity of anticoagulation for filter efficacy, vascular catheter-related bloodstream infections, variations in proficiency levels among healthcare professionals regarding CRRT modalities, especially in operating the CRRT machines, high nursing workload, frequent nursing turnover, occurrences of hypophosphatemia, variability in CRRT prescribing patterns, and issues related to communication among stakeholders. This research sheds light on the primary risks associated with CRRT and provides practical and viable strategies for effective management. Furthermore, the Bowtie diagram developed as part of this study serves as a valuable tool for visually representing the healthcare system and facilitating the identification of system-related risks within healthcare settings.

Study on Quantitative Evaluation Method for Failure Risk Factors of the High-Temperature and High-Pressure Downhole Safety Valve

Downhole safety valves are essential equipment for oil and gas extraction, and it is crucial to carry out a downhole safety valve failure risk evaluation and reliability analysis to ensure the safety of oil and gas production. In order to improve the operation and maintenance management level of downhole safety valves and explore the key failure risk factors of downhole safety valves, this study firstly carries out a Failure Mode and Criticality Analysis of downhole safety valves; identifies the causes of failure of downhole safety valves and the consequences of accidents through the Bow-tie method; and quantitatively evaluates the failure risk factors based on the improved Decision-making Trial and Evaluation Laboratory method and obtains the influence and importance ranking of 14 types of failure risk factors. Specific preventive measures for key failure risk factors are proposed in several aspects: optimising the structural design of downhole safety valves, improving the processing and manufacturing process, setting up an efficient field management team, carrying out equipment operation and maintenance management training, establishing a field failure response mechanism, and setting up an intelligent O&M management platform for downhole safety valves. The research results of this study are conducive to improving the reliability of downhole safety valves, ensuring the safety and integrity of on-site operation and maintenance management, and providing theoretical guidance for the analysis of the risk of failure and operation and maintenance management of downhole safety valves.

Using fuzzy cognitive map in bow tie method for dynamic risk assessment of spherical storage tanks: A case study

The present study aimed to perform a dynamic risk assessment of liquefied petroleum gas (LPG) in spherical storage tanks using the Hazard and Operability (HAZOP) method. The “LPG release from spherical storage tank” scenario was determined to be a top event based on the risk level. The causes and consequences of this scenario were then specified using the Bow-Tie method. Additionally, fuzzy cognitive mapping (FCM) was utilized to identify the most critical threats, consequences, and effective barriers in a dynamic approach. Results showed that fracture/rupture in pipelines/a storage tank due to fire had the highest output degree and was identified as the most influential threat in the occurrence of the LPG release. Fatality/injury due to fire and explosion had the highest input degree and was more influenced by the release of LPG as the main consequence in the selected scenario. The findings of this study enabled us to make a logical decision about effective barriers for avoiding and minimizing the release of LPG and its threats and consequences based on the fuzzy cognitive map. Moreover, the results of this study showed that the FCM method could determine the most critical nodes with a higher degree and represent their relationships.

Hazard Identification Using Task Risk Assessment Method and Bowtie Analysis (Case Study: PT. Varia Usaha Beton)

PT. Varia Usaha Beton is a subsidiary of PT. Semen Indonesia Beton, which produces various types of products. PT Varia Usaha Beton (BSP Purwokerto) has an open work area where there are potential hazards such as physical factors, chemical factors and ergonomic factors. The aim of this research is to identify hazards, assess risks and control risks in the production process of ready-mixed concrete so that workplace accidents can be minimized. The methods used in this research are task risk assessment and bowtie analysis. Based on the research results, it was found that 1 risk belonged to the low category, 27 risks belonged to the medium category, and 11 risks belonged to the high category. Based on the bow-tie method, the major risks are exposure to fly ash and cement dust, risk of diesel spills, and risk of electric shock. The main causes of workplace accidents are pipe leaks and improper diesel filling. The main risk effects of workplace accidents are worker injury, and fire. The bowtie analysis method determines that the risk of electric shock is due to a damaged cable and the existing protective barrier is intended to replace the damaged cable. This risk has consequences, namely injuries to workers.

Risk Assessment of Aircraft Refueling Activities at the Indonesian Flight Academy Banyuwangi Using the Bowtie Method and Shell Model Human Factor

This study aims to assess the risks involved in aircraft refueling activities at the Indonesian Pilot Academy in Banyuwangi, using the Bowtie method and the SHELL Model Human Factor. The study adopts a qualitative descriptive approach to understand the emerging risks and human factors associated with the activity. Based on the research findings, fire risk emerges as the most dominant. These risks are then analyzed using the Bowtie method and the SHELL Model Human Factor to gain a comprehensive understanding of the causes and consequences of fire risk. Several identified causes of fire risk include non-compliance with procedures, absence of fuel flow measuring devices and fuel drum handling equipment, visual impairment due to sunlight, and inadequate temporary fuel storage conditions. Potential impacts include fire and significant damage to the aircraft. This research makes an important contribution to enhancing safety by providing relevant safety recommendations for aircraft refueling activities at the Indonesian Pilot Academy in Banyuwangi.

Safety, health, and environmental risk assessment of the aromatic outlet of Imam Khomeini Petrochemical Company using LOPA and fuzzy-LOPA and pollutants and control actions using the Bow-tie method.

Today, with the development of the industry, the occurrence of accidents caused by the release and explosion of chemical and toxic substances in industrial units has increased, and these accidents sometimes cause irreparable damage to human life and the environment. According to a study by the American Petroleum Institute, of the recent major accidents in the last 30 years, 44% are related to machinery failure and 12% are caused by unknown factors and lack of information. Therefore, equipment risk control is aimed at preventing large and dangerous accident. The present study, the performance of LOPA and fuzzy-LOPA methods was compared toward the risk assessment of Imam Khomeini Petrochemical Company under certainty and uncertainty of data. This comparison was done in order to a conceptual method with high certainty to assess high-level hazards leading to health and safety risks and environmental pollution. First, the health, safety hazards and environmental aspects were identified via the HAZOP method. Then, a risk assessment was performed using the LOPA method. The fuzzification, severity, and likelihood of each risk were considered as an input variable and risk probability as an output variable. Finally, was the methods used in our analysis were compared and the Bow-tie software was used to draw a Bow-tie diagram to control and reduce the risks. As a result, a total of 50 safety and health hazards and 37 environmental aspects were identified in the aromatic outlet of the studied company using the HAZOP method. The most critical risks identified were operational activities in feed and product tanks; flammable materials pumping; blocking the flare path; and releasing H2S gas. The results showed that the production of air pollutants in the power supply unit, disposal of waste from reactor tanks, disposal of waste from condensate tanks, and fire and explosion of the reactor are high-level environmental risks. In the conditions of uncertainty or the absence of information related to the probability and severity of the risk scenario, among the mentioned methods. The result showed that errors in the risk assessment were reduced to an acceptable extent by using Fuzzy LOPA method.

ANALISIS KECELAKAAN KERJA PADA STRUKTUR BAWAH BLENDING SILO PROYEK “EPC TALAVERA” TUBAN MENGGUNAKAN METODE BOWTIE

The "EPC Talavera" Tuban Project is one of the major projects located in Tuban. Given that the construction of the Blending Silo is being built at a considerable height and certainly requires a large foundation structure, the construction of the Blending Silo carries a relatively high risk of workplace accidents. The purpose of this research is to identify workplace accident risks and evaluate the causes, impacts, and risk responses to accidents during the construction of the substructure of the Blending Silo in the "EPC Talavera" project. To determine the dominant workplace accident risks, risk assessment is performed using probability and severity calculations based on the Risk Management Standard AS/NZ 4360:1999, resulting in an Importance Index value. The method used to evaluate the causes, impacts, and risk responses to workplace accidents is the Bowtie Analysis Method. The results of this research indicate that the most dominant workplace accident risks are the risk of workers being pierced by sharp equipment, the risk of fingers getting caught in the bar bender machine, and the risk of workers being shocked/electrocuted by electrical currents. Based on the bowtie method, the most dominant causes of workplace accidents are scattered sharp equipment, careless/inattentive/unhealthy workers, inadequate equipment, poor bar bender machine conditions, bar bender machine operating methods, exposed welding tool cables, rainy/extreme weather conditions, and electrical current leaks in welding tool bodies. The most dominant impacts of workplace accidents are minor injuries, serious injuries/death, fires, and damage to the bar bender machine. Using the bowtie method, risk responses or controls for the most dominant workplace accident risks are also analyzed, along with an analysis of escalation factors and their controls.

Implementasi Manajemen Risiko Penularan Covid-19 terhadap Perawat Indonesia di Kuwait melalui Metode Bowtie

Purpose: The purpose of this service is to obtain an overview of the implementation of COVID-19 transmission risk management for Indonesian nurses working in Kuwait through the Bowtie method. Methodology: This research is quantitative in nature using a scientific approach to the implementation of risk management for the transmission of COVID-19 in Indonesian nurses working in Kuwait where these nurses work in various health services in Kuwait. This research was conducted using a descriptive analytic method using a cross-sectional study design. Result: The results of the study found that: 1) The application of risk management (risk control or mitigation) in handling COVID-19 in various health services in Kuwait such as the implementation of hospitalization for staff who were confirmed positive and the existence of a COVID-19 vaccination program had a significant effect on the transmission of COVID-19 -19 in Indonesian Nurses working in Kuwait. 2) The level of knowledge about the importance of preventing and transmitting COVID-19 to Indonesian nurses in Kuwait has a very significant influence on the transmission of COVID-19. 3) The level of compliance of Indonesian nurses with infection prevention control measures or health protocols has a significant effect on the transmission of COVID-19 in Indonesian nurses working in various health services in Kuwait.

Implementasi Manajemen Risiko Penularan Covid-19 terhadap Perawat Indonesia di Kuwait melalui Metode Bowtie

Purpose: The purpose of this service is to obtain an overview of the implementation of COVID-19 transmission risk management for Indonesian nurses working in Kuwait through the Bowtie method. Methodology: This research is quantitative in nature using a scientific approach to the implementation of risk management for the transmission of COVID-19 in Indonesian nurses working in Kuwait where these nurses work in various health services in Kuwait. This research was conducted using a descriptive analytic method using a cross-sectional study design. Result: The results of the study found that: 1) The application of risk management (risk control or mitigation) in handling COVID-19 in various health services in Kuwait such as the implementation of hospitalization for staff who were confirmed positive and the existence of a COVID-19 vaccination program had a significant effect on the transmission of COVID-19 -19 in Indonesian Nurses working in Kuwait. 2) The level of knowledge about the importance of preventing and transmitting COVID-19 to Indonesian nurses in Kuwait has a very significant influence on the transmission of COVID-19. 3) The level of compliance of Indonesian nurses with infection prevention control measures or health protocols has a significant effect on the transmission of COVID-19 in Indonesian nurses working in various health services in Kuwait.

Risk Analysis of Hot Working in Confined Space Using Confined Space Risk Analysis (CRSA) and Bowtie Analysis Method on LPG Tanker Repair Process

Confined space is a room that is large enough and has a configuration in such a way that workers can enter and do work in it. In the ship repair process it is not uncommon to do it in a confined space area. . The purpose of writing this final project is to identify hazards and carry out risk assessments in hot working in confined spaces in the LPG tanker ship repair process so that the dominant hazard is obtained, the causes and consequences of the dominant hazard are identified, and the right dominant risk control can be identified. This study begins with the identification of the characteristics of confined space on ships by grouping them into 7 risk categories of confined space. Then carry out risk identification by explaining the components of a risk, including: types of hazards, dangerous work, dangerous events and the consequences that can occur. After that, an initial risk assessment was carried out for hot working in confined spaces on ship repairs presented in matrix form. After that, risk control is carried out and the final risk reassessment for hot working in confined space on ship repair is carried out by continuing the matrix that was previously made. In the final stage, an analysis is carried out using the bowtie method to analyze the causes, impacts, and controls of these risks.

Combining the bow-tie method and fuzzy logic using Mamdani inference model

As a hybrid tool, Bowtie might be effective as a qualitative tool. However, when the quantitative contribution is considered, it relies on databases, and as such, the analysis is affected by the subjective judgment of the specialist, data variability, or lack of data which may lead to vagueness and imprecise information. Fuzzy logic can help to shed light on this matter as it is capable of resembling human reasoning. The approach offers various mechanisms to overcome these uncertainties. This paper proposes a combination of Bowtie and fuzzy logic, using a case study concerning the rupture of isobutane storage tank. The Mamdani inference method is investigated. Additionally, the Fussel-Vasely equation was used to calculate the critical importance for each basic event, which brings a complementary understanding of the system. Six tests were performed to analyse the frequencies and fussel-vasely numbers of the five basic events: “PI” (Pressure Indicator), “LIAH” (Level and Indicator Alarm High), “HE” (Human Error), “SV” (SAFE VALVE) and “DS” (Disposal System). The analysis showed that the basic event “SV” as the most critical event, followed by “LIAH” and “Human Error”.

A Risk Treatment Strategy Model for Oil Pipeline Accidents Based on a Bayesian Decision Network Model.

Risk treatment is an effective way to reduce the risk of oil pipeline accidents. Many risk analysis and treatment strategies and models have been established based on the event tree method, bow-tie method, Bayesian network method, and other methods. Considering the characteristics of the current models, a risk treatment strategy model for oil pipeline accidents based on Bayesian decision network (BDNs) is proposed in this paper. First, the quantitative analysis method used in the Event-Evolution-Bayesian model (EEB model) is used for risk analysis. Second, the consequence weights and initial event likelihoods are added to the risk analysis model, and the integrated risk is obtained. Third, the risk treatment strategy model is established to achieve acceptable risk with optimal resources. The risk treatment options are added to the Bayesian network (BN) risk analysis model as the decision nodes and utility nodes. In this approach, the BN risk analysis model can be transformed into a risk treatment model based on BDNs. Compared to other models, this model can not only identify the risk factors comprehensively and illustrate the incident evolution process clearly, but also can support diverse risk treatment strategies for specific cases, such as to reduce the integrated risk to meet acceptable criterion or to balance the benefit and cost of an initiative. Furthermore, the risk treatment strategy can be updated as the risk context changes.

Comparative analytical study of the results of environmental risk assessment of urban landfills approach: bowtie, network analysis techniques (ANP), TOPSIS (case study: Gilan Province).

Most landfill projects run in a dynamic and complex environment; therefore, uncertainty and risk are inherent. To improve the performance and reduce the damage caused by waste, risk study and its management have become necessary in implementing landfill location projects. As a result of the biodegradation of organic matter in waste, landfills produce various materials such as leachate, and gas. Therefore, it is necessary to conduct environmental risk assessments so that the destructing factors and their effects on the environment can be identified, and subsequently, control and management solutions offered. In the present study, the author has identified the most critical risks of construction phases and operation of landfills in Gilan province, using the Analytic Network Process (ANP), Delphi, and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) techniques. According to the results, the environmental sector represents the highest risk in the construction and operation phases. Therefore, solutions for reducing or eliminating adverse outcomes have been proposed according to the bowtie method. Solutions to reduce or eliminate the adverse effects of leachate leakage from the landfill floor that causes pollution and infiltration into groundwater: installation of a conventional control system. Routing of landfill gases by passing soil filters at the highest points of landfills using the bowtie method is recommended. The results showed that anthropogenic activities related to sanitary landfilling of waste have greatly affected Gilan province in recent years.

An extended FRAM method to check the adequacy of safety barriers and to assess the safety of a socio-technical system

Safety barriers are used in the system to prevent unwanted events and accidents. Traditional approaches like fault tree or bow-tie method use linear accident models without considering complex interactions of failures of safety barriers. The present paper presents an extended FRAM model to identify required safety barriers and proposes a safety analysis method to predict the system's safety. The initial step of the method is to identify the necessary main and auxiliary functions to achieve the system goal. The later step is to determine the necessary safety functions to execute the main functions to achieve the system goal and to resist variability in performing the main and related auxiliary functions. A simple mathematical model is proposed to assess system safety based on the performance of existing barriers. The method is described with the help of a case study, the LNG ship-to-ship transfer process. The paper compares the extended FRAM method with other methods such as Bow-tie, FRAM-STPA, and Bayesian network. Analysis shows that FRAM can qualitatively, quantitatively, and dynamically assess system safety. The most vital point of FRAM lies in its capability of effective qualitative evaluation, which considers coupling between functions and related aspects, can be presented graphically, and future actions can be taken accordingly.

A Risk Analysis Method of Cable Fire in Utility Tunnel Based on a Bayesian Network

Recently, the fire safety of tunnels is attracting more and more attention with the utility tunnel springing up in major cities of China. Faced with challenges from fires in utility tunnels, fire risk analysis is critical and essential to discover the weaknesses of risk. It serves as the foundation of regulatory decision-making on whether to take appropriate measures to reduce risk. This study combines a Bayesian network (BN) model and a bow-tie (BT) method to propose a fire risk analysis method to predict the probability of cable fire in utility tunnels. First, cable fire risk factors and five potential accident scenarios are analyzed by BT method; Second, to avoid the influence of uncertain factors in BT, the optimized BN model is applied to the prediction analysis of cable fire probability, which can consider the actual development of cable fire in utility tunnel. This novel approach can better reveal the causal relationship between events and determine the critical basic events by sensitivity analysis. Finally, the probability of cable fire ignition occurrence and scenarios probabilities are periodically updated using the cumulative information collected during a time interval. The results show that this approach can assist in dealing with the uncertainty problem in utility tunnel and the optimized model is more in line with the reality by comparing the results before model optimization.

APPLICATION OF AN IMPROVED BOWTIE METHOD IN A CSM-COMPLIANT RISK ASSESSMENT OF A CHANGE INTRODUCED IN THE EU RAILWAY SYSTEM

The issue of managing the risk associated with introducing changes to the railway system is very important from the point of view of safety management, as any change can significantly reduce the level of safety of a railway system. For this reason, such changes are regulated at the European Union (EU) level through a dedicated legal act known as the Common Safety Method for risk assessment (CSM). The example presented in this paper is a portion of the analysis carried out for an Estonian freight carrier with a bowtie method, which we improved so that it fully complies with the CSM requirements. This analysis concerns a change consisting of allowing the possibility of a freight train being driven by one person (with no assistant driver). The case study presented in the paper, although limited due to confidentially issues, allows a full description of how to use the proposed method in real-world applications.