From visual representation to signal flow connection: A new modeling approach for STAMP

Abstract

System-Theoretic Accident Model and Processes (STAMP) and System-Theoretic Process Analysis (STPA) have emerged as novel perspectives for analyzing hazards in control systems, revealing previously unnoticed hazards that traditional failure propagation analyses may overlook. Their contribution, therefore, holds significant implications in hazard analysis, but a challenge arises in the modeling of cl systems at a fairly detailed level, where it becomes inefficient to distinguish the flow of a particular signal. To address this concern, this paper proposes the digital representation of the modeling elements and the correlation between the elements in STAMP. The digitally represented STAMP can be used to distinguish the flow of a particular signal and can also be used as a basis for the implementation of supportive functions for STPA. Therefore, potential applications, e.g. highlighting or reorganizing a specific signal flow, incomplete part identification within a control structure, impact of the unavailability of a system element, are also discussed in this paper. The authors believe that the digital representation of STAMP and its applications proposed in this paper will improve the efficiency of the process of performing STAMP/STPA at a detailed level.