System-Theoretic Process Analysis Based on SysML/MARTE and NuSMV

Abstract

Systems Theoretical Accident Model and Process (STAMP), which considers system safety as an emergent property of the system, is a more effective accident/loss causality model for modern complex systems. Based on STAMP, System Theoretical Process Analysis (STPA) has attracted increasing attention as a new approach to hazard analysis, and relevant international standards are being developed. However, STPA is mainly performed manually, leading to inefficiencies, and constructs models in non-standard language, hindering the integration with existing systems engineering. STPA-SN (STPA based on SysML/MARTE and NuSMV) is proposed to build model in SysML, describing the timing with MARTE (Modeling and Analysis of Real-Time and Embedded Systems), transform SysML model into NuSMV model and output loss scenarios automatically with model checker. An application example of STPA-SN is provided to demonstrate potentials for higher efficiency of analysis and for collaboration with SysML-based systems engineering.

A novel STPA approach to software safety and security in autonomous maritime systems

“…Important software interactions, often described as VF and hidden in the classical STPA, are modeled here in sequence diagrams. 1 If necessary, the dynamic state evolution can be modeled by the employment of state transition diagrams, as has been demonstrated by Zhong et al [56] .…”

Synthesis of a Controller Algorithm for Safety-Critical Systems

“…Zhong et al [5] propose an adaption of STPA based on SysML/MARTE and NuSMV (STPA-SN), which aims to improve the formalization of STPA. Their proposal includes (i) the use of the SysML internal block diagram in STPA step "Model the control structure"; (ii) definition of the unsafe control action as a state and the unsafe control action as a command received by the controlled process (instead of issued by the controller) in STPA step "Identify unsafe control actions"; and (iii) automatic definition of loss sce-narios through the conversion between SysML state machine diagrams and NuSMV models.…”

“…Recently, there have been significant advances in assessing the information identified in the STPA analysis through the combination of STPA with NuSMV [5], UPPAAL [6], or Event-B [7]. Although these approaches provide ways to support the safety assessment of the systems, they rely on the expertise of the designer in UPPAAL, Event-B, or NuSMV.…”