Systems-Theoretic Accident Model And Processes Research Articles

STPA systemic approach for OHS and operational risk analysis of data glove use in 4.0 assembly

The complexity of manufacturing is rising considerably and it enhances through the introduction of new technologies to the system. Advancements in new technologies (in this study data gloves) and their application in the 4.0 assembly context will bring about new and emerging occupational health and safety (OHS) and operational risks. This study aims to apply STAMP (Systems-Theoretic Accident Model and Processes)-based approach to analyze these risks when a data glove is introduced to an assembly system. The application of STPA (Systems-Theoretic Process Analysis) on realistic case studies provides a systemic view of systems’ control structure from OHS and operational concerns. Findings indicate that STPA is a promising method for OHS and operational risk analysis when a wearable is introduced to a complex assembly system, especially in designing step. However, technology readiness level limits access to numerical and detailed data in providing insight into intensity of the different control structure’s effect and system components and their interactions on the studied system.

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 approach for quantitative importance analysis of safety DI&C systems in the nuclear field

As the digitalization of the safety instrumentation and control (I&C) systems in the nuclear field causes very complex interactions between their components and difficulty in securing quantitative failure information of each component, there are considerable challenges in analyzing them via probabilistic safety assessment (PSA), the typical safety analysis framework of existing safety I&C systems. This study proposes a new approach to resolve these challenges. The suggested method develops a system model based on the systems-theoretic accident model and processes (STAMP) philosophy and assigns weights to specific components according to design information and operation strategies instead of quantitative failure information. Based on the assigned weights, the importance of each component is derived by calculating the effect of a single component failure on the overall I&C functions. The methodology is explained through simple examples and validated with an analysis of a real-world system. The proposed approach is expected to be useful in deriving insights from the design stages to the improvement stages for more diverse I&C systems by enabling quantitative importance analysis without failure information.

A methodology to perform dynamic risk assessment using system theory and modeling and simulation: Application to nuclear batteries

Accidents may occur as a result of complex dynamic processes in interconnected socio-technical systems. Such accidents cannot be explained solely in terms of static chains of failures. Therefore, the traditional Probabilistic Risk Assessment (PRA) framework, which stands on the consideration that accidents are caused by direct failures or chains of events, is not apt to describe the dynamic behavior of the relevant Systems, Structures and Components (SSCs) and assess the risk. This work proposes a novel framework that embeds (i) System-Theoretic Accident Model and Processes (STAMP) principles to guide a qualitative exploration of the SSC threats and hazards, (ii) Modeling and Simulation (M&S) to investigate the SSC dynamic behavior during accidental scenarios, and (iii) the Goal-Tree Success-Tree Master Logic Diagram (GTST-MLD) framework to assess risk quantitatively. The integration of STAMP, M&S and GTST-MLD allows a systematic analysis to provide risk insights, with due account to the SSC dependencies and interactions, and enables a dynamic assessment of the risk profile.The effectiveness of the proposed framework is shown by means of its application to the safety assessment of Nuclear Batteries (NBs), a unique class of nuclear micro-reactors which is gaining attention as a transportable, flexible, affordable, and distributed low-carbon power source.

Application of integrated STAMP-BN in safety analysis of subsea blowout preventer

Blowout preventer (BOP) plays a key role in preventing blowout accidents from occurring during offshore or deepwater drilling. The safety of BOP is affected by diverse components and interactions among them. It is vital to identify the crucial failure modes using safety assessment method. To perform a qualitative, quantitative, and systematic safety assessment of BOP, this paper presents an integrated method—using the system-theoretic accident model and process (STAMP)-Bayesian network (BN)—for evaluation of the structure safety and prediction of the failure scenarios. In the proposed method, STAMP is used to identify the failure scenarios by establishing a hierarchical control and feedback model that tallies with the BOP structure, while BN is adopted to calculate the probabilities of potential failure modes based on the outcomes of STAMP. The approach is then explored in a case study where factors regarding humans, components and control systems, and constraints and control relationships among them are all considered. The results demonstrate the feasibility of the integrated method as a way of performing a safety analysis for BOP. This research overcomes the deficiencies of traditional methods that cannot effectively evaluate the interactions of components, thereby providing a reference for safety/risk analyses of complex systems.

Learning from Incidents in Socio-Technical Systems: A Systems-Theoretic Analysis in the Railway Sector

Post mortem incident investigations are vital to prevent the occurrence of similar events and improve system safety. The increasing interactions of technical, human and organizational elements in modern systems pose new challenges for safety management, demanding approaches capable of complementing techno-centric investigations with social-oriented analyses. Hence, traditional risk analysis methods rooted in event-chain reactions and looking for individual points of failure are increasingly inadequate to deal with system-wide investigations. They normally focus on an oversimplified analysis of how work was expected to be conducted, rather than exploring what exactly occurred among the involved agents. Therefore, a detailed analysis of incidents beyond the immediate failures extending towards socio-technical threats is necessary. This study adopts the system-theoretic accident model and process (STAMP) and its nested accident analysis technique, i.e., causal analysis based on systems theory (CAST), to propose a causal incident analysis in the railway industry. The study proposes a hierarchical safety control structure, along with system-level safety constraints, and detailed investigations of the system’s components with the purpose of identifying physical and organizational safety requirements and safety recommendations. The analysis is contextualized in the demonstrative use of a railway case. In particular, the analysis is instantiated for a 2011 incident in the United Kingdom (UK) railway system. Hence, the CAST technique requires information regarding incidents, facts and processes. Therefore, the case study under analysis provided the information to analyze the accidents based on system theory, in which the results of the analysis prove the benefits of a CAST application to highlight criticalities at both element- and system-level, spanning from component failure to organizational and maintenance planning, enhancing safety performance in normal work practices.

Applying AcciMap and STAMP to the analysis of human error in complex manual assembly

AbstractIn sectors such as aerospace manufacturing, human errors in the assembly of complex products can negatively impact quality, productivity, and safety. Until now, the analysis of assembly errors has focused more on the immediate human‐system interface and less on broader organizational factors. This article presents a case study‐based analysis of assembly errors in the aeronautical industry using the systemic methods AcciMap and Systems‐Theoretic Accident Model and Processes (STAMP). We seek to provide the company with elements to build a quality improvement strategy that considers human factors and ergonomics from a systemic perspective. The data and information necessary to conduct the analysis came from a project carried out at an aerospace manufacturing facility over a period of 12 months. The team had direct and recurrent access to primary data sources and communication with various stakeholders. A total of 31 influencing factors were identified with AcciMap at different levels within the manufacturing system. STAMP made it possible to model the sociotechnical control structure of the assembly process and identify several control flaws leading to hazards. The analysis shows that systemic methods require a high level of understanding of the manufacturing system and access to relatively high amounts of data and information. Therefore, direct contact with the field and stakeholders is crucial. Training quality specialists on systemic methods could support its use and help to close the gap between theory and practice. Globally, the field of quality in manufacturing could benefit from using systemic methods when deemed necessary.

Energy storage for large scale/utility renewable energy system - An enhanced safety model and risk assessment

Renewables recorded 26.2% of global electricity generation in 2018 and expected to rise to 45% by 2040 attributed to nations commitment to reduce greenhouse gases since the signing of Paris agreement 2015. Policies friendly towards the development of renewable energy sources are developed, but the risk and safety assessment are still based on the traditional analytic and probabilistic risk-based assessment practices such as Event Tree Analysis (ETA), Fault Tree Analysis (FTA), Failure Mode Effect Analysis (FMEA), Hazards Identification (HAZID), Hazards and Operability (HAZOP). These practices are viewed as own envelop of methodology whilst sharing a lot of common parameters and working principles. Analytic approach is becoming ineffective with increasingly complex energy system integrating renewables. There are on-going research proposing systemic based risk assessment approach but without incorporating advantages from analytic approach. The aim of this paper is to provide a comprehensive analysis of risk and safety assessment methodology for large scale energy storage currently practices in safety engineering today and comparing Causal Analysis based on System-Theoretic Accident Model and Process (STAMP) and Systems-Theoretic Process Analysis (STPA) with fault tree analysis, FMEA, HAZID, HAZOP. This paper demonstrated that systemic based risk assessment such Systems Theoretic Process Analysis (STPA) is suitable for complicated energy storage system but argues that element of probabilistic risk-based assessment needs to be incorporated. This is to ensure holistic risk assessment is performed to energy storage system and provide a new viewpoint for underlying safety model in integrated manner based on performance requirements, human factor, environmental, management, safety, and legislation. The results describe the improvement of risk assessment technique via Systems Theoretic Process Analysis-Hybrid (STPA-H) using a case study of grid connected Photovoltaic (PV) system with Li-ion battery storage. The hazards and mitigation measures identified from STPA-H are presented and compared with existing approach. STPA-H technique proposed is applicable for different types of energy storage for large scale and utility safety and risk assessment. This paper is expected to benefit Malaysian government with the progression of Large-Scale Solar 3 (LSS3) and serve as reference to future energy system risk assessment.

Modified quantitative systems theoretic accident model and processes (STAMP) analysis: A catastrophic ship engine failure case

Despite the rapid advancement of technology and the increasing complexity of systems, conventional accident analysis techniques developed many years ago are still used in numerous sectors. On the other hand, these approaches are limited in detecting all underlying causes of accidents in complex socio-technical systems. In recent years, system theory-based novel accident analysis techniques have been proposed to address this issue. Systems-Theoretic Accident Model and Processes (STAMP) is one of these innovative analytic techniques with a strong detection capability. The method has the ability for analyzing human, organization, hardware, software, external factor components, and their interactions in a dynamic structure. However, despite the method's strong analysis capacity, it is a shortcoming that STAMP is a qualitative method. This study aims to present a hybrid quantitative methodology for complex system accidents based on a system engineering perspective to fill this gap. In this context, a real catastrophic marine diesel engine incident was analyzed to prove the applicability and effectiveness of the methodology. According to the analysis results, the main causes of the case incident were systematically determined as 80% human factor, 13% hardware & software factor, and 7% external factor.

A discussion on the implementation of the Polar Code and the STCW Convention’s training requirements for ice navigation in polar waters

In 2017, the International Maritime Organization (IMO) implemented the International Code for Ships Operating in Polar Waters (Polar Code), with mandatory requirements covering the Arctic and Antarctic Oceans. In this conjunction, the International Convention on Standards of Training, Certification and Watchkeeping (STCW) were amended in 2018. New training requirements were made applicable for dedicated personnel in charge of a navigational watch on ships with a Polar Ship Certificate (PSC) operating in polar waters. In association with the new training requirements amending the STCW Convention, the IMO, and Transport Canada (flag state authority) signed a Memorandum of Understanding in 2017, for Canada to develop and deliver four regional capacity-building “train-the-trainer” workshops. The objectives of these events were to assist maritime education and training (MET) institutes in enhancing the skills and competence of instructors, to develop competence-based STCW training programs, for dedicated personnel on ships operating in polar waters. This paper examines the first workshop conducted in Canada (2019), to understand the mechanisms in the interaction taking place between the IMO and the Canadian workshop developers and instructors, using the System Theoretic Accident Model and Processes (STAMP). Individual expert interviews are performed, with the main contributors directly involved in developing and conducting the workshop, to evaluate the event’s contribution to improving and specifying the STCW Convention’s training requirements, as referenced in the Polar Code, for seafarers operating in polar waters.

Using systems theory for additional risk detection in boiler explosions in Brazil

Recent technological advances have allowed some human activities, including those related to safety, to be automated. However, these advances increased the complexity of sociotechnical systems, representing exponential growth of interactions between humans, computers, machines, and the environment. Moreover, growing productive and economic pressures demand safer and more reliable products and projects, at lower costs and time than those practised by competitors. To cope with this complexity and set of conflicting objectives, the STAMP (Systems-Theoretic Accident Model and Processes) emerged as a novel approach to analyse processes and accidents. In this study, an overview of boiler accidents in Brazil is presented and a causal analysis based on STAMP (CAST) is conducted to revisit one of the worst boiler accidents in the Brazilian scenario. Even without direct participation in the investigations, additional and more relevant risk factors are evidenced. Furthermore, it was found that government agencies generally refrain from reviewing their own control actions contributing to the hazard, limiting their potential improvements. This suggests a need for companies and government agencies to adopt new paradigms of risk and accident analysis and to work together for a systemic safety improvement approach.

A STAMP-based approach to quantitative resilience assessment of chemical process systems

Chemical process systems (CPSs) involve complex dynamic processes. Besides, the emergent and uncertain hazards and disruptions cannot be identified entirely and prevented by conventional methods. In those situations, resilience for CPSs plays an essential role in absorbing, adapting to disruptions, and restoring from damages. Systemic modeling plays a vital role in assessing resilience. A system-based analysis model, system-theoretic accident model, and process (STAMP) can provide a robust framework. This paper develops a comprehensive methodology to systematically model and assess system resilience. The STAMP is employed to model and analyze the system safety of a process system. A new method of dynamic resilience assessment is then proposed to quantify the resilience of the system. The proposed method is applied to the diesel oil hydrogenation system. The results show that it quantifies the resilience of complex process systems considering human and organizational factors in a dynamic manner.

WEB-BASED RADIOTHERAPY INCIDENT ANALYSIS SYSTEM

Objective: A web-based radiotherapy incident analysis system was developed and tested for safer radiotherapy implementation. Radiation dose incidence reporting is a known evaluation method for learning from the errors that occur during the radiotherapy procedure. Established as a safety-critical, non-punitive, just-culture system, the waterfall model was employed in the construction process of the system to identify and learn from incidents, non - conformance, and near-misses in radiotherapy settings. Method: The theoretical framework of the thesis was based on the Systems-Theoretic Accident Model and Processes (STAMP). The system algorithms were designed to identify sixty-two (62) radiotherapy errors. Results: The results of system implementation require patient test data that was selected based on the PRISMA 2009 method. Records identified through the radiotherapy manual database were 4479 patient data set. The system reported 1215 treatment sessional errors which are equivalent to 219 patient errors when analyzed with simple descriptive statistics. Incident data were identified directly by the system, in terms of incident level, form and patient incident, year dependent, site-specific, primary site incident, and treatment status. Frequency of error types were 10% incidents, 85% non-conformance and 5% near-misses. Patient error types identified 58.447% incidents, 13.699% non-conformance and 27.854% near-misses. Conclusion and Recommendation: Treatment status gave an overview of the quality of clinical decisions and implementation in the management of the patient. In future iterations, error tagging and solution recommendation parts with supervised machine learning algorithms would be made available to show the types of errors captured and chances of mitigating risks in terms of percentages for incident learning.

Reliability assessment of autonomous vehicles based on the safety control structure

The recent social trends and accelerated technological progress culminated in the development of autonomous vehicles (AVs). Reliability assessment for AV systems is in high demand before its market launch. In safety-critical systems (SCSs) such as AV systems, the reliability concept should be broadened to consider more safety-related issues. In this paper, reliability is defined as the probability that the system performs satisfactorily for a given period of time under stated conditions. This paper proposes a reliability assessment framework of AV, consisting of three main stages: (i) modeling the safety control structure through the Systems-Theoretic Accident Model and Processes (STAMP); (ii) mapping the control structure and functional relationships to a directed acyclic graph (DAG); and (iii) construct a Bayesian network (BN) on DAG to assess the system reliability. The fully automated (level 5) vehicle system is shown as a numeric example to illustrate how this suggested framework works. A brief discussion on involving human factors in systems to analyze lower levels of automated vehicles is also included, demonstrating the need for further research on real case studies.

A new accident causation theory based on systems thinking and its systemic accident analysis method of work systems

Major accidents such as the Space Shuttle Challenger disaster in the USA, the Bhopal Disaster in India, the Fukushima nuclear accident in Japan, and the Tianjin Port fire and explosion accident in China, have occurred all over the world. Safety scientists are always trying to understand why these accidents happened and how to prevent these accidents. Accident models and theories form the basis for many safety research fields and practices. However, there is no universally accepted model with useful elements relating to understanding accident causation, although many accident causation models exist. A new accident causation theory named the Interaction Theory of Hazard-Target System (ITHTS) is proposed based on Systems-Theoretic Accident Model and Processes (STAMP) and Risk Management Framework (RMF), which not only incorporates human, organisational and technological characteristics in the same framework, but also considers the sociological factors such as legislative, regulatory, and cultural factors. On the other hand, a new systemic accident analysis method of work systems (SAAMWS) is proposed based on ITHTS and STAMP because ITHTS cannot be applied directly in accident analysis. We choose Tianjin Port fire and explosion accident as a case study to demonstrate the explanatory power of Interaction Theory of Hazard-target System and the feasibility of the new accident analysis method. Further research needs to be done to assess the reliability and validity of this new systemic accident analysis method.

Integrity control analysis of natural gas hydrate production wellbore using system method and game theory

Natural gas hydrate (NGH) is an outstanding alternative to conventional energy due to its cleanliness and excellent energy density. However, there are still a series of problems needed to be solved before the commercial production of hydrates is realized, one of which is wellbore integrity. Different from the traditional fossil energy wellbore, the integrity degradation of hydrate wellbore has obvious man-machine and complex system characteristics. Hence, NGH production wellbore barrier classification is defined firstly, as well as failure level and consequence judgment. The system-theoretic accident model and process (STAMP) and system-theoretic process analysis (STPA) methods are applied to establish a hierarchical control and closed-loop model of the NGH production wellbore system. Through inappropriate integrity control actions (ICAs) analysis, well integrity engineers play a leading role in the control loop, and a comprehensive monitoring network helps engineers make effective decisions. Game theory is utilized to study the senior superintendent's supervision strategy and the oil service company's investment strategy for wellbore integrity management selection preference in the test production cycle. The results show that the strategic preference of the executor is related to the frequency of maintenance and supervision, and basically does not change during the production cycle. The growth rate of policy preference value for supervisor decreases with the increase of ratio of partial strategy, but it does not affect the initial preference value. The findings of this study can provide support for wellbore integrity management during test or commercial production of offshore hydrates.

The past and present of System-Theoretic Accident Model And Processes (STAMP) and its associated techniques: A scoping review

Targeting the analysis of socio-technical complexity, the System-Theoretic Accident Model and Processes (STAMP) was developed to engineer safer systems. Since its inception in the early 2000s, STAMP and its associated techniques, namely the System-Theoretic Process Analysis (STPA) and the Causal Analysis based on System Theory (CAST), have attracted increasing interest as suitable approaches for safety studies. Nonetheless, a literature review on their applications is lacking. This paper fills this gap via a scoping literature survey on contributions indexed in academic journals and conference proceedings. Through a systematic analysis of 321 eligible documents, this research presents a comprehensive examination of relevant features for STAMP, STPA and CAST since 2003, such as the system type and domain of analysis, coverage and completeness of the analytical and methodological steps, respectively, as well as alterations and/or enrichments of their original versions. The bibliometric findings from primary, secondary and non-empirical research contributions are discussed to critically reflect on the past and present of STAMP and its associated techniques, and possible future directions are highlighted.

A STAMP analysis of the staff safety management system in residential Aged Care

Residential aged care facilities are facing increased demand for a high quality of care. High rates of employee injury and illness in these facilities suggest there are issues in the current work health and safety (WHS) management system. This study used a Systems Theoretic Accident Model and Processes (STAMP) model to examine the points of conflict and gaps within the residential aged care WHS management system. Focus groups and interviews were conducted with work health & safety professionals (7), aged care home managers (2), and work health & safety regulator inspectors (3), to validate the STAMP model, identify points of conflict and gaps within the system, and identify potential solutions to improve the effectiveness of WHS management. Participants identified gaps and points of conflict at all levels of the system. The majority of controls and feedback for staff safety were located at the ‘Aged Care Home Management’ level. The application of a STAMP model in private residential aged care services identified a tension between quality of care for residents and safety of staff. Reduction of workplace injuries will require the addressing of conflicts between the competing priorities of staff and residents; linking work health and safety accreditation to quality of care accreditation based funding may provide some incentive to address this important issue.

STAMP-based causal analysis of the Coal Mine Major Accident: From the perspective of safety process

In response to the increasingly complex causes of coal mine accidents, a system analysis method — Systems Theoretic Accident Model and Processes (STAMP) is used in the analysis of major accidents in coal mines. Based on a comparative analysis of multiple causation models, this paper will use STAMP model to control coal mine safety system from many aspects of coal mine accident cause level. Finally, the causes of such accidents are summarized and compared with the existing analytical conclusions. The results demonstrate that using the STAMP model to analyse major accidents in coal mines can lead to more comprehensive conclusions than that of traditional causal models. In addition to equipment defects and illegal operations by workers, the fundamental reason underlying accidents is that the elimination or delay of the feedback loop between the layers in the layered control structure of the system after changes occur in the system’s external environment.

Teaming with industrial cobots: A socio‐technical perspective on safety analysis

AbstractCollaborative human–machine interaction will be progressively intensified in industrial applications. The aim of this article is to examine current approaches to cobot safety by showing that these approaches can additionally benefit from systems thinking methods. The first part of this article covers a narrative literature review on predominantly techno‐centric robot safety approaches, with a strong focus on containing kinetic energy and ensuring separation with humans. The second part introduces systems thinking methods to analyze a socio‐technical perspective on cobot safety, including joint cognitive systems and distributed cognition perspectives. This explorative research dimension is expected to overcome an overly narrow interpretation of safety issues, anticipating the challenges ahead in ever more complex cobot applications. This article embraces a socio‐technical perspective to explore the potential of Joint Cognitive Systems to manage risk and safety in cobot applications. Three systemic safety analysis approaches are presented and tested with a demonstrator case study concerning their feasibility for cobot applications: System‐Theoretic Accident Model and Processes (STAMP); Functional Resonance Analysis Method (FRAM); and Event Analysis of Systemic Teamwork (EAST). These methods each provide interesting extensions to complement the traditional understanding of risk as required by current and future industrial cobot implementations. The power of systemic methods for safer and more efficient cobot operations lies in revealing the distributed and emergent result from joint actions and overcoming the reductionist view from individual failures or single agent responsibilities. The safe operation of cobot applications can only be achieved through alignment of design, training, and operation of such applications.