Road accidents involving commercial vehicles are showing an alarming trend from year to year. Ironically the accidents involving heavy vehicles would involve the third party such as cars, motorcycles and other vehicles; due to several factors such as fatigue, speeding, tire defect, road defect, road design issue and risky driving. When occurred, it normally involved higher number of fatalities. Therefore, in order to improve the situation with regards to road accidents involving heavy vehicles, especially buses, a holistic road safety strategy is necessary and vital towards better road safety in the future. This paper aims to understand Safety Management System of bus operators using Systems-Theoretic Accident Model and Processes (STAMP) by analysing three case studies namely Genting, Tapah and Pagoh bus crashes in 2013, 2015 and 2016, respectively. Hazard analysis and causal factors were carried out on the bus operators' Safety Management System by using STPA (Systems- Theoretic Process Analysis) and CAST (Causal Analysis based on STAMP). The results of the analyses showed that the operating process could be revised or redesigned to improve the existing safety system. Moreover, STAMP could be a very useful approach to understand the whole safety system that may involve several complex factors.
 
 

STAMP (System-Theoretic Accident Model and Processes) is a relatively new approach to safety assessment methodology and post-accident cause analysis; its prime developer is Nancy Leveson of MIT. STAMP is a holistic system-level approach to overall organizational structure and to technical operations and design. It takes a comprehensive look at all possible organizational and technical system influences that can ultimately affect the safety of technical processes and product designs in whatever scenarios or environments in which they operate or to which they are subjected. Of course, the process can be applied equally to both reliability of performance and security, in addition to safety.

Surveying work-as-done in post-operative delirium risk factors collection and diagnosis monitoring

This paper aims to identify the main cause of the hose whipping phenomenon (HWP) in air refueling, and come up with effective preventive measures. The system-theoretic accident model and process (STAMP), i.e., the system-theoretic process analysis (STPA), was adopted to evaluate the safety of air refueling. Then, the evaluation results were verified with a self-designed simulation validation model. The results show that the HWP is controlled by the docking speed, reel mechanism, and designed hose length; the swing range and tension change of the hose increased under inappropriate speed control; reel control could end the hazardous state of the hose within 50s after docking; the HWP occurred after the hose length was shortened from 22m to 14m. The research findings provide a reference for the prevention of the HWP.

The phased application of STAMP, FRAM and RAG as a strategy to improve complex sociotechnical system safety

STAMPing out MRI Simulation Hazards with a System-Theoretic Accident Model and Processes Approach to Proactive Hazard Assessment

A Delphi study of human factors methods for the evaluation of adaptation in safety-related organisations

Out of control? Using STAMP to model the control and feedback mechanisms surrounding identity crime in darknet marketplaces

Organizational and institutional factors affecting high-speed rail safety in Japan

Ships complexity is continuously increasing and lots of action controls, traditionally carried out by crew members, are now managed and executed by the on-board automation systems. The relation among humans and automation system shall be studied with specific attention to their mutual interface and interaction issues, in order to better pursue safety. The STAMP (System-Theoretic Accident Model and Processes)-based tool named STPA (System Theoretic Process Analysis) consists the following steps: identify system hazards; draw functional control structure; identify unsafe control actions (UCAs); identify accident scenarios; formulate decisions and recommendations. In this paper an approach to model the relations among human operator and automation, based on STPA, will be proposed. An application case will be developed considering a large passenger ship and the specific hazard of dead ship condition (energy black-out). In case of navigation close to the shore and heavy weather condition, this situation can rapidly evolve into a ship loss.

To solve the task-process-safety problem of airborne weather radar system, a set of case-inspired safety analysis method is proposed based on the STAMP(Systems-Theoretic Accident Model and Process). Taking weather radar system's task process in approaching stage as an example, a hierarchical control structure is constructed to identify unsafe control actions during the task process, and analyze the potential hazard causes associating with unsafe control actions. Then a safe flight control structure model is constructed and the accident case of Delta Airlines is analyzed to optimize the model. The safety of system task process is improved through putting forward the safe constraints which can control the propagation mechanism of accident. It is indicated through the above analysis that the method can comprehensively identify the potential hazard causes of system, and provide technical support for the safety design of airborne weather radar system.

An urban pipeline accident model based on system engineering and game theory

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

ABSTRACT The ‘8.12’ Tianjin Port fire and explosion are an extraordinarily major accident that involved hazardous chemicals, resulting in 165 fatalities, 798 injuries, and a direct economic loss of 6.866 billion yuan. This study introduced causal analysis based on systems theoretic accident model and process (STAMP) (CAST) to identify the key controllers in the control structure, and the control and feedback relationships among them. By using CAST, this study not only identified the traditional human and organizational factors within the physical company which are responsible for the operation process, but also identified the outside factors within the public political structure which are responsible for the public safety and security. In this study, the safety and security of hazardous chemical accident are integrated into a unified framework in which the key difference between safety and security in the intention of the actors is reframed as a general loss prevention problem. This study shows the applicability of the CAST approach in the analysis of hazardous chemical accidents and provides different perspectives and methods to develop safety and security interventions in a hazardous chemical accident.

Deriving of Time Constants in Timed Automata for Hazard Transition Sequences for STAMP/STPA

Falls can have serious consequences for people, leading to restrictions in mobility or, in the worst case, to traumatic-based cases of death. To provide rapid assistance, a portable fall detection system has been developed that is capable of detecting fall situations and, if necessary, alerting emergency services without any user interaction. The prototype is designed to facilitate reliable fall detection and to classify several fall types and human activities. This solution represents a life-saving service for every person that will significantly improve assistance in the case of fall events, which are a part of daily life. Additionally, this approach facilitates independent system operation, since the system does not depend on sensor or network units located within a building structure. This article also introduces fall analysis. To guarantee functional safety, a hazard analysis method named system-theoretic accident model and processes (STAMP) is applied.

A CAST-based causal analysis of the catastrophic underground pipeline gas explosion in Taiwan

Accident models provide a conceptual representation of accident causation. They have been applied to environments that have been exposed to poisonous or dangerous substances that are hazardous in nature. The home environment refers to the indoor space with respect to the physical processes the of indoor climate, e.g., temperature change, which are not hazardous in general. However, it can be hazardous when the physical process is in some states, e.g., a state of temperature that can cause heat stroke. If directly applying accident models in such a case, the physical processes are missing. To overcome this problem, this paper proposes an accident model by extending the state-of-the-art accident model, i.e., Systems-Theoretic Accident Model and Process (STAMP) with considering physical processes. Then, to identify causes of abnormal system behaviors that result in physical process anomalies, a hazard analysis technique called System-Theoretic Process Analysis (STPA) is tailored and applied to a smart home system for indoor temperature adjustment. The analytical results are documented by a proposed landscape genealogical layout documentation. A comparison with results by applying the original STPA was made, which demonstrates the effectiveness of the tailored STPA to apply in identifying causes in our case.

Due to the complex mechanical structure and control process of escalator emergency braking systems (EEBS), traditional hazard analysis based on the event chain model have limitations in exploring component interaction failure in such a complex social-technical system. Therefore, a hazard analysis framework is proposed in this paper for hazard analysis of complex electromechanical systems based on system-theoretic accident model and process (STAMP). Firstly, basic principles of STAMP are introduced and comparison with other hazard analysis methods is conducted, then the safety analysis framework is proposed. Secondly, a study case is performed to identify unsafe control actions of EEBS from control structures, and a specific control diagram is organized to recognize potential example casual scenarios. Next, comparison between fault tree analysis and STAMP for escalator’s overturned accident shows that hazards related to component damaged can be identified by both, while hazards that focus on components interaction can only be identified by STAMP. Besides, single control way and tandem operation process are found to be the obvious causal factors of accidents. Finally, some improvement measures like decibel detection or vibration monitoring of key components are suggested to help the current broken chain detection to trigger the anti-reversal device for a better safe EEBS.

A safety management system (SMS) is the common means used by organizations to assess organizational performance with respect to the safety and well-being of people, property and the natural ecosystem. A SMS provides confidence to diverse stakeholders that organizational safety is at an appropriate level and fulfils the applicable regulatory standards. As a multifaceted system for organizational safety assessment, ensurance and assurance, the evaluation of the design and operational use of SMS is a complex process. An evaluation needs to provide evidence about how well the design and operation of an SMS complies with applicable standards and how well the methods used in the SMS implementation support the organizational policies and practical work. In the maritime domain, SMS is broadly applied. However, there are few theoretically rooted SMS design approaches, and there is a lack of frameworks to evaluate how well the SMS is designed and how effectively it operates. This paper proposes an initial evaluation framework for the design and operational use of a maritime SMS design approach based on Systems-Theoretic Accident Model and Processes (STAMP), realist evaluation and Bayesian Networks. This framework is applied for a case study of vessel traffic services (VTS) Finland to test its relevance and ability to guide the SMS design. The experiences gained in the case study, and the related discussion on the framework, can guide further research in this area. Ultimately, the work can be used as a basis for developing maritime SMS auditing processes, based on specific theoretical and methodological approaches.