scholarly journals An Accident Model with Considering Physical Processes for Indoor Environment Safety

2019 ◽  
Vol 9 (22) ◽  
pp. 4732 ◽  
Author(s):  
Zhengguo Yang ◽  
Yuto Lim ◽  
Yasuo Tan
Keyword(s):  
Home Environment ◽  
Physical Process ◽  
Process Analysis ◽  
Hazard Analysis ◽  
Heat Stroke ◽  
Indoor Climate ◽  
Physical Processes ◽  
Indoor Space ◽  
Analysis Technique ◽  
Accident Causation

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.

scholarly journals A Novel System-Theoretic Matrix-Based Approach to Analysing Safety and Security of Cyber-Physical Systems

Telecom ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 536-553
Author(s):  
Lin-Shen Liew ◽  
Giedre Sabaliauskaite ◽  
Nandha Kumar Kandasamy ◽  
Choong-Yew William Wong
Keyword(s):  
Process Analysis ◽  
Hazard Analysis ◽  
Cyber Physical Systems ◽  
Monitoring And Control ◽  
Residential Energy ◽  
Monitoring And Control System ◽  
Physical Systems ◽  
Safety Risks ◽  
Analysis Technique ◽  
And Control

Cyber-Physical Systems (CPSs) are getting increasingly complex and interconnected. Consequently, their inherent safety risks and security risks are so intertwined that the conventional analysis approaches which address them separately may be rendered inadequate. STPA (Systems-Theoretic Process Analysis) is a top-down hazard analysis technique that has been incorporated into several recently proposed integrated Safety and Security (S&S) analysis methods. This paper presents a novel methodology that leverages not only STPA, but also custom matrices to ensure a more comprehensive S&S analysis. The proposed methodology is demonstrated using a case study of particular commercial cloud-based monitoring and control system for residential energy storage systems.

scholarly journals Cybersafety Approach to Cybersecurity Analysis and Mitigation for Mobility-as-a-Service and Internet of Vehicles

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1220
Author(s):  
Chee Wei Lee ◽  
Stuart Madnick
Keyword(s):  
Autonomous Vehicles ◽  
Process Analysis ◽  
Hazard Analysis ◽  
Urban Mobility ◽  
Internet Of Vehicles ◽  
On Demand ◽  
Software Updates ◽  
Levels Of Automation ◽  
New Generation ◽  
Convergence Of Technologies

Urban mobility is in the midst of a revolution, driven by the convergence of technologies such as artificial intelligence, on-demand ride services, and Internet-connected and self-driving vehicles. Technological advancements often lead to new hazards. Coupled with the increased levels of automation and connectivity in the new generation of autonomous vehicles, cybersecurity is emerging as a key threat affecting these vehicles. Traditional hazard analysis methods treat safety and security in isolation and are limited in their ability to account for interactions among organizational, sociotechnical, human, and technical components. In response to these challenges, the cybersafety method, based on System Theoretic Process Analysis (STPA and STPA-Sec), was developed to meet the growing need to holistically analyze complex sociotechnical systems. We applied cybersafety to coanalyze safety and security hazards, as well as identify mitigation requirements. The results were compared with another promising method known as Combined Harm Analysis of Safety and Security for Information Systems (CHASSIS). Both methods were applied to the Mobility-as-a-Service (MaaS) and Internet of Vehicles (IoV) use cases, focusing on over-the-air software updates feature. Overall, cybersafety identified additional hazards and more effective requirements compared to CHASSIS. In particular, cybersafety demonstrated the ability to identify hazards due to unsafe/unsecure interactions among sociotechnical components. This research also suggested using CHASSIS methods for information lifecycle analysis to complement and generate additional considerations for cybersafety. Finally, results from both methods were backtested against a past cyber hack on a vehicular system, and we found that recommendations from cybersafety were likely to mitigate the risks of the incident.

scholarly journals A Novel Hazard Analysis and Risk Assessment Approach for Road Vehicle Functional Safety through Integrating STPA with FMEA

2020 ◽  
Vol 10 (21) ◽  
pp. 7400
Author(s):  
Lei Chen ◽  
Jian Jiao ◽  
Tingdi Zhao
Keyword(s):  
Risk Assessment ◽  
Process Analysis ◽  
Hazard Analysis ◽  
International Standards ◽  
Functional Safety ◽  
Road Vehicles ◽  
Effect Analysis ◽  
Automotive Safety ◽  
Safety Requirements ◽  
Assessment Approach

ISO26262: 2018 is an international functional safety standard for electrical and/or electronic (E/E) systems within road vehicles. It provides appropriate safety requirements for road vehicles to avoid unreasonable residual risk according to automotive safety integrity levels (ASILs) derived from hazard analysis and risk assessment (HARA) required in the ISO26262 concept phase. Systems theoretic process analysis (STPA) seems to be designed specifically to deal with hazard analysis of modern complex systems, but it does not include risk evaluation required by most safety related international standards. So we integrated STPA into Failure Mode and Effect Analysis (FMEA) template to form a new method called system theoretic process analysis based on an FMEA template, STPAFT for shot, which could not only meet all the requirements of the concept phase in ISO26262, but also make full use of the advantages of the two methods. Through the focus of FMEA on low-level components, STPAFT can obtain more detailed causal factors (CFs), which is very helpful for derivation of safety goals (SGs) and the functional safety requirements (FSRs) in the concept phase of ISO26262. The application of STPAFT is described by the case study of fuel level estimation and display system (FLEDS) to show how the concept phase of ISO26262 could be supported by STPAFT.

scholarly journals System-Theoretic Process Analysis (STPA) for Hazard Analysis in Complex Systems: The Case of “Demand-Side Management in a Smart Grid”

Systems ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 33 ◽  
Author(s):  
Stylianos Karatzas ◽  
Athanasios Chassiakos
Keyword(s):  
Smart Grid ◽  
Complex Systems ◽  
Energy Management ◽  
Demand Response ◽  
Energy Demand ◽  
Process Analysis ◽  
Hazard Analysis ◽  
Energy Market ◽  
System Modelling ◽  
Home Energy Management

Inelasticity of demand along with the distributed energy sources and energy market democratization pose significant challenges which have considerable negative impacts on overall grid balance. The need for increased capacity and flexibility in the era of energy market digitalization has introduced new requirements in the energy supply network which could not be satisfied without continuous and costly local power network upgrades. Additionally, with the emergence of Smart Homes (SHs) and Home Energy Management (HEM) systems for monitoring and operating household appliances, opportunities have arisen for automated Demand Response (DR). DR is exploited for the modification of the consumer energy demand, in response to the specific conditions within the electricity system (e.g., peak period network congestion). In order to optimally integrate DR in the broader Smart Grid (SG) system, modelling of the system parameters and safety analysis is required. In this paper, the implementation of STPA (System-Theoretic Process Analysis) structured method, as a relatively new hazard analysis technique for complex systems is presented and the feasibility of STPA implementation for loss prevention on a Demand Response system for home energy management, and within the complex SG context, is examined. The applied method delivers a mechanism useful in understanding where gaps in current operational risk structures may exist. The STPA findings in terms of loss scenarios can be used to generate a variety of safeguards to ensure secure operational control and in implementing targeted strategies through standard approaches of risk assessment.

A Comprehensive Hazard Analysis Technique for Safety-Critical Automotive Systems

2001 ◽  
Author(s):  
Sanket Amberkar ◽  
Barbara J. Czerny ◽  
Joseph G. D'Ambrosio ◽  
Jon D. Demerly ◽  
Brian T. Murray
Keyword(s):  
Hazard Analysis ◽  
Safety Critical ◽  
Automotive Systems ◽  
Analysis Technique

scholarly journals Comparison of Diesel-Electric with Hybrid-Electric Propulsion System Safety Using System-Theoretic Process Analysis

2019 ◽  
Author(s):  
V Bolbot ◽  
G Theotokatos ◽  
E Boulougouris ◽  
D Vassalos
Keyword(s):  
Electric Propulsion ◽  
Process Analysis ◽  
Hazard Analysis ◽  
Propulsion System ◽  
Cruise Ship ◽  
Propulsion Systems ◽  
Electric Propulsion System ◽  
Automation And Control ◽  
Hybrid Electric ◽  
And Control

Cruise ship industry is rapidly developing, with both the vessels size and number constantly growing up, which renders ensuring passengers, crew and ship safety a paramount necessity. Collision, grounding and fire are among the most frequent accidents on cruise ships with high consequences. In this study, a hazard analysis of diesel-electric and hybrid-electric propulsion system is undertaken using System-Theoretic Process Analysis (STPA). The results demonstrate significant increase in potential hazardous scenarios due to failures in automation and control systems, leading to fire and a higher number of scenarios leading to propulsion and power loss in hybrid-electric propulsion systems than on a conventional cruise-ship propulsion system. Results also demonstrate that STPA enhancement is required to compare the risk of two propulsion systems.

scholarly journals dfgcompare: a library to support process variant analysis through Markov models

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amin Jalali ◽  
Paul Johannesson ◽  
Erik Perjons ◽  
Ylva Askfors ◽  
Abdolazim Rezaei Kalladj ◽  
...  
Keyword(s):  
Performance Metrics ◽  
Markov Models ◽  
Process Analysis ◽  
Cohort Analysis ◽  
Data Driven ◽  
Software Support ◽  
Cohort Comparison ◽  
Analysis Technique ◽  
Variant Analysis ◽  
And Performance

Abstract Background Data-driven process analysis is an important area that relies on software support. Process variant analysis is a sort of analysis technique in which analysts compare executed process variants, a.k.a. process cohorts. This comparison can help to identify insights for improving processes. There are a few software supports to enable process cohort comparison based on the frequencies of process activities and performance metrics. These metrics are effective in cohort analysis, but they cannot support cohort comparison based on the probability of transitions among states, which is an important enabler for cohort analysis in healthcare. Results This paper defines an approach to compare process cohorts using Markov models. The approach is formalized, and it is implemented as an open-source python library, named dfgcompare. This library can be used by other researchers to compare process cohorts. The implementation is also used to compare caregivers’ behavior when prescribing drugs in the Stockholm Region. The result shows that the approach enables the comparison of process cohorts in practice. Conclusions We conclude that dfgcompare supports identifying differences among process cohorts.

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