Systemic Accident Models Research Articles

Comparison of the theoretical elements and application characteristics of STAMP, FRAM, and 24Model: A major hazardous chemical explosion accident

Owing to the flammable, explosive, and toxic characteristics of hazardous chemicals, chemical accidents always result in significant losses. Analysis of the parameters of process safety is an effective way to prevent hazardous chemical accidents and reduce losses. To promote the application of systemic accident models in practice, in this study, we clarify the theoretical elements of such models based on the development of system thinking and system science. Then, we discuss the characteristics of a new systemic model called 24Model and its systems thinking. We explore the differences in the practical application of different systemic models (System-Theoretic Accident Model and Processes (STAMP), Functional Resonance Accident Model (FRAM), and 24Model by analyzing a major hazardous chemical explosion accident that occurred in Tianjiayi Chemical Co., Ltd. in China. The results show that the elements of the systemic accident model are the system structure, component relationship, and dynamic behaviors. 24Model is proven to be a new systemic accident model developed by utilizing sequential models. The comparative results of the three analysis methods show that FRAM is suitable for accident prediction rather than accident analysis. STAMP and 24Model perform better in terms of the usability and reliability of accident analysis. Although STAMP fails to elaborately indicate the internal organizational causes of the accident, it is suitable for a small number of accidents in socio-technical systems. 24Model is a structured method for accident analysis and safety management frame of organization. With the classified accident causes and fewer training resources, it is more suitable for a number of accidents statistics and analysis. Finally, a universal frame to prevent hazardous chemical accidents is provided for companies and regulators.

A novel methodology to measure safety level of a process plant using a system theory based method (STAMP)

Major accidents continue to happen in the process industry and often have serious consequences. There are questions on how these accidents happen and how we can monitor safety in a process plant to prevent these accidents.In order to explain how accidents happen, different accident causation models have been used, whereas most of them were developed long time ago. Significant changes have occurred in the industry and traditional models may have limitations in identifying causes of accidents in modern industry within complex sociotechnical environment. Consequently, new accident models based on systems theory have been developed lately.Safety is often measured by number of accidents, mishaps or near misses. This retrospective approach cannot help enough to prevent accidents. In this paper, a novel methodology is introduced to measure safety level in process plants with the purpose of preventing accidents. This methodology is based on Systems Theoretic Accident Model and Processes (STAMP), which is one of the systemic accident model developed recently. The methodology is tested using real data from a process plant and obtained promising results are provided in this paper.

Engineering ethics within accident analysis models

The purpose of this paper is to further investigate engineering ethics and its gap within accident analysis models. In this paper, at first, the role of human factors in the occurrence of accidents is presented. Then engineering ethics as an element of human factors is proposed. It is suggested that engineering ethics can provide engineers with the necessary guidelines to avoid possible accidents arising from their decisions and actions. In addition, the Challenger and Columbia space shuttle case studies that demonstrate the role of engineering ethics in the prevention and occurrence of accidents are discussed. Then sequential, epidemiological, and systemic accident analysis models are briefly investigated and negligence of engineering ethics as a gap in the accident analysis models is described. At the end, we suggest that by implementing engineering ethics as a controller within the system boundary in systemic accident models we may be able to identify and prevent the ethical causes of accidents.

Tracing New Safety Thinking Practices in Safety Investigation Reports

Modern safety thinking and models focus more on systemic factors rather than simple cause-effect attributions of unfavourable events on the behaviour of individual system actors. This study concludes previous research during which we had traced practices of new safety thinking practices (NSTPs) in aviation investigation reports by using an analysis framework that includes nine relevant approaches and three safety model types mentioned in the literature. In this paper, we present the application of the framework to 277 aviation reports which were published between 1999 and 2016 and were randomly selected from the online repositories of five aviation authorities. The results suggested that all NSTPs were traceable across the sample, thus followed by investigators, but at different extents. We also observed a very low degree of using systemic accident models. Statistical tests revealed differences amongst the five investigation authorities in half of the analysis framework items and no significant variation of frequencies over time apart from the Safety-II aspect. Although the findings of this study cannot be generalised due to the non-representative sample used, it can be assumed that the so-called new safety thinking has been already attempted since decades and that recent efforts to communicate and foster the corresponding aspects through research and educational means have not yet yielded the expected impact. The framework used in this study can be applied to any industry sector by using larger samples as a means to investigate attitudes of investigators towards safety thinking practices and respective reasons regardless of any labelling of the former as “old” and “new”. Although NSTPs are in the direction of enabling fairer and more in-depth analyses, when considering the inevitable constraints of investigations, it is more important to understand the perceived strengths and weaknesses of each approach from the viewpoint of practitioners rather than demonstrating a judgmental approach in favour or not of any investigation practice.

Systemic accident analysis models: A comparison study between AcciMap, FRAM, and STAMP

Nowadays, different accident causation models are used to explain how accidents happen, whereas most of them were developed long time ago. There is an argument that significant changes have occurred in the industry and traditional models may have limitations in identifying causes of accidents in modern industry within complex socio‐technical environment. Consequently, new accident models based on systems theory have been introduced, but they are mainly used by academic researchers. Among systemic accident models, Systems‐Theoretic Accident Model and Processes (STAMP), Functional Resonance Accident Model (FRAM), and AcciMap methods have been identified as the most frequently cited models.This article presents a case study‐based comparison of these three models. STAMP and FRAM are used to analyze the Chevron Richmond refinery accident, which is investigated by U.S. Chemical Safety and Hazard Investigation Board (CSB). CSB investigation team developed an AcciMap of the accident.The results are compared and differences are discussed. In conclusion, STAMP is likely to be more instrumental and comprehensive in identifying contributing factors and generating recommendations. © 2018 American Institute of Chemical Engineers Process Saf Prog 38: e12002, 2019

A new framework to model and analyze organizational aspect of safety control structure

Following the principles of systemic accident models, in this paper we presented a new framework for modeling organizational aspect of hierarchical safety control structure in complex Socio-Technical Systems. In fact, we introduced a Specific Organizational Feedback Control Loop together with a Customized Process Model to narrow down System Theoretic Process Analysis (STPA) risk analysis method. Clearly, this modification can be able to adjust STPA for deficiency analysis of organizational safety control structure. As a case study, we used this framework in an aircraft maintenance industry, as a sample system. Indeed, we modeled and analyzed this system’s organizational safety control structure by our new framework. We demonstrated that, the new framework, as a modified version of STPA, can accurately model and analyze the organizational control mechanisms.

Applying Systemic Accident Model to Learn from Near-Miss Incidents of Train Maneuvering and Operation

Abstract: This study proposes a novel method for safety management in train operation and maneuvering based upon Hollnagel’s functional resonance analysis method (FRAM), which assumes that components of a system interact mutually and resonantly. According to the original FRAM, the general functions of train drivers’ and conductors’ tasks are defined, and the normal procedure of a common case is represented. Our method first attempts to replay how fluctuations of some of the tasks propagate through the entire system. Then we examine whether a countermeasure found by replaying is valid under various situations. In this way, we demonstrate that our method is able to detect latent hazards of the system as well as to identify how the system is influenced by various external and internal changes.

Risk management in power system control centres

This article is the result of investigations which indicated that conditions, particularly safety management, at power system control centres were either contributing factors or causal factors in the large-scale blackouts which occurred in 2003 all over the developed world. An exploratory research methodology was followed in an attempt to determine the baseline level of safety management within the control centres along with the applicability of the safety management concepts. The experience survey developed followed a flexible line of questioning which illuminated the context and produced both quantitative and qualitative data. The results indicated that there was no support for the proposition that the control centre business environment is becoming more complex and the risk management was not adequate; neither was there support for the proposition that the risk management strategies were based on more than one class of accident model. There was however support for the proposition that control centres do not use systemic accident models on which to base their accident prevention techniques. Key words: Risk management, accident prevention, safety management.

Factor Analysis for Imperfect Maintenance Planning at Nuclear Power Plants by Cognitive Task Analysis

Imperfect maintenance planning was frequently identified in domestic nuclear power plants. To prevent such an event, we analyzed causal factors in maintenance planning stages and showed the directionality of countermeasures in this study. There is a pragmatic limit in finding the causal factors from the items based on report descriptions. Therefore, the idea of the systemic accident model, which is used to monitor the performance variability in normal circumstances, is taken as a new concept instead of investigating negative factors. As an actual method for analyzing usual activities, cognitive task analysis (CTA) was applied. Persons who experienced various maintenance activities at one electric power company were interviewed about sources related to decision making during maintenance planning, and then usual factors affecting planning were extracted as performance variability factors. The tendency of domestic events was analyzed using the classification item of those factors, and the directionality of countermeasures was shown. The following are critical for preventing imperfect maintenance planning: the persons in charge should fully understand the situation of the equipment for which they are responsible in the work planning and maintenance evaluation stages, and they should definitely understand, for example, the maintenance bases of that equipment.

Systemic accident risk assessment in air traffic by Monte Carlo simulation

A systemic accident model considers accidents as emergent phenomena from variability and interactions in a complex system. Air traffic risk assessments have predominantly been done by sequential and epidemiological accident models. In this paper we demonstrate that Monte Carlo simulation of safety relevant air traffic scenarios is a viable approach for systemic accident assessment. The Monte Carlo simulations are based on dynamic multi-agent models, which represent the distributed and dynamic interactions of various human operators and technical systems in a safety relevant scenario. The approach is illustrated for a particular runway incursion scenario, which addresses an aircraft taxiing towards the crossing of an active runway while its crew has inappropriate situation awareness. An assessment of the risk of a collision between the aircraft taxiing with an aircraft taking-off is presented, which is based on dedicated Monte Carlo simulations in combination with a validation approach of the simulation results. The assessment particularly focuses on the effectiveness of a runway incursion alert system that warns an air traffic controller, in reducing the safety risk for good and reduced visibility conditions.