STAMP-based Analysis Research Articles

Passenger rail station safety improvement and analysis of end-of-track collisions based on systems-theoretic accident modeling and processes (STAMP)

Purpose At the US passenger stations, train operations approaching terminating tracks rely on the engineer’s compliant behavior to safely stop before the end of the tracks. Noncompliance actions from the disengaged or inattentive engineers would result in hazards to train passengers, train crewmembers and bystanders at passenger stations. Over the past decade, a series of end-of-track collisions occurred at passenger stations with substantial property damage and casualties. This study’s developed systemic model and discussions present policymakers, railway practitioners and academic researchers with a flexible approach for qualitatively assessing railroad safety. Design/methodology/approach To achieve a system-based, micro-level analysis of end-of-track accidents and eventually promote the safety level of passenger stations, the systems-theoretic accident modeling and processes (STAMP), as a practical systematic accident model widely used in the complex systems, is developed in view of environmental factors, human errors, organizational factors and mechanical failures in this complex socio-technical system. Findings The developed STAMP accident model and analytical results qualitatively provide an explicit understanding of the system hazards, constraints and hierarchical control structure of train operations on terminating tracks in the US passenger stations. Furthermore, the safety recommendations and practical options related to obstructive sleep apnea screening, positive train control-based collision avoidance mechanisms, robust system safety program plans and bumping posts are proposed and evaluated using the STAMP approach. Originality/value The findings from STAMP-based analysis can serve as valid references for policymakers, government accident investigators, railway practitioners and academic researchers. Ultimately, they can contribute to establishing effective emergent measures for train operations at passenger stations and promote the level of safety necessary to protect the public. The STAMP approach could be adapted to analyze various other rail safety systems that aim to ultimately improve the safety level of railroad systems.

STAMP-based analysis of deepwater well control safety

The complexity of a deepwater well control system makes defining appropriate safety requirements with traditional safety analysis methods difficult. Hence, there is a need for a complex systems approach for better understanding the development and prevention of accidents during deepwater drilling. Differing from traditional methods based on reliability theory, we use the system-theoretic accident model and process (STAMP) and system-theoretic process analysis (STPA) methods to establish a hierarchical control and feedback loop model of a well control system. In view of the characteristics of complexity and dynamism, the safety analysis is regarded as a system control and feedback problem in this work. Using this model, the systematic hazards and safety-related constraints are firstly defined, the safety control structure (SCS) is then established, the inappropriate control actions (ICAs) are identified in the next step, and the key factors that contribute to ICAs are finally determined. Guided by the STAMP/STPA, we construct the process of well control to simulate the consequences of ICAs during deepwater drilling by using the dynamic multiphase simulation software, OLGA. The simulation takes the lack of control actions and the provided control actions of a late shut-in as examples. The STAMP/STPA method proves to be an effective solution for evaluating the safety of deepwater well control from the perspectives of control and constraint. By modeling the process of a well kick, shut-in, and well killing, it was quantitatively indicated that the rational control actions within a certain time period can prevent accidents from occurring and escalating, thereby ensuring the safety of the system. The differences between traditional methods and STAMP/STPA are compared in this paper, and the limitations that need to be solved in the future are pointed out.

A STAMP-based causal analysis of the Korean Sewol ferry accident

The increased complexity of socio-technical systems has revealed the limited contributions of existing event-based accident analysis methods on sustainable safety improvements. Systems-Theoretic Accident Model and Processes (STAMP) – constructed upon Systems Theory – deploys a holistic approach to safety and provides broad insights into accident causality via the integration of the analysis from both direct and indirect factors involved. A dedicated STAMP-based analysis is conducted in this paper by taking the recent Sewol ferry tragedy as an example, to illustrate the utility of applying the STAMP-Model to the maritime transportation domain and to stimulate a broader view of accident mechanisms that expands casual analysis beyond immediate physical failures to a systemic view. Some recommendations are developed for continuous improvements and corrective actions to prevent such catastrophic accident from future occurrences.

STAMP-Based HRA Considering Causality Within a Sociotechnical System: A Case of Minuteman III Missile Accident.

The study contributes to human reliability analysis (HRA) by proposing a method that focuses more on human error causality within a sociotechnical system, illustrating its rationality and feasibility by using a case of the Minuteman (MM) III missile accident. Due to the complexity and dynamics within a sociotechnical system, previous analyses of accidents involving human and organizational factors clearly demonstrated that the methods using a sequential accident model are inadequate to analyze human error within a sociotechnical system. System-theoretic accident model and processes (STAMP) was used to develop a universal framework of human error causal analysis. To elaborate the causal relationships and demonstrate the dynamics of human error, system dynamics (SD) modeling was conducted based on the framework. A total of 41 contributing factors, categorized into four types of human error, were identified through the STAMP-based analysis. All factors are related to a broad view of sociotechnical systems, and more comprehensive than the causation presented in the accident investigation report issued officially. Recommendations regarding both technical and managerial improvement for a lower risk of the accident are proposed. The interests of an interdisciplinary approach provide complementary support between system safety and human factors. The integrated method based on STAMP and SD model contributes to HRA effectively. The proposed method will be beneficial to HRA, risk assessment, and control of the MM III operating process, as well as other sociotechnical systems.

STAMP-based analysis on the railway accident and accident spreading: Taking the China–Jiaoji railway accident for example

Each hazard analysis technique is based on a model of accident causation. Most accident models regard accidents as resulting from a chain or sequence of events, such models are fit for accidents caused by failures of physical components and for relatively simple systems, but suffer from serious deficiencies when they are applied to software-intensive, complex engineering systems. Recently, a new accident model called System-Theoretic Accident Models and Process (STAMP) for system safety has been proposed, it is based on control theory and enforces constraints on hazards and thereby prevent accidents. In this paper, taking the China–Jiaoji railway accident happened on April 28, 2008 as an example, the STAMP approach has been used to analyze the railway accident and some improvement measures have been proposed. As the occurrence of one accident can cause many other accidents happen, based on the STAMP-based analysis, the accident spreading processes have also been discussed and modeled, which will be helpful to analyze accidents spreading in a broad sense and establish effective emergent measures for accident response management.