Advanced Hazard Analysis and Risk Assessment in the ISO 26262 Functional Safety Standard Using Rigorous Simulation

Abstract Hazard analysis is the core of numerous approaches to safety engineering, including the functional safety standard ISO-26262 (FuSa) and Safety of the Intended Function (SOTIF) ISO/PAS 21448. We focus on addressing the immense challenge associated with the scope of training and testing for rare hazard for autonomous drivers, leading to the need to train and test on the equivalent of >108 naturalistic miles. We show how risk can be estimated and bounded using the probabilistic hazard analysis. We illustrate the definition of hazards using well-established tests for hazard identification. We introduce a dynamic hazard approach, whereby autonomous drivers continuously monitor for potential and developing hazard, and estimate their time to materialization (TTM). We describe systematic TTM modeling of the various hazard types, including environment-specific perception limitations. Finally, we show how to enable accelerated development and testing by training a neural network sampler to generate scenarios in which the frequency of rare hazards is increased by orders of magnitude.

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ISO 26262 - The Relevance and Importance of Qualitative and Quantitative Methods for Safety and Reliability Issues Regarding the Automotive Industry

Journal of Konbin ◽

10.2478/v10040-008-0175-7 ◽

2010 ◽

Vol 14-15 (1) ◽

pp. 165-176

Author(s):

Marco Schlummer ◽

Dirk Althaus ◽

Andreas Braasch ◽

Arno Meyna

Keyword(s):

Risk Assessment ◽

Automotive Industry ◽

Quantitative Methods ◽

Hazard Analysis ◽

Functional Safety ◽

Automotive Safety ◽

Iso 26262 ◽

Qualitative And Quantitative ◽

Qualitative And Quantitative Methods ◽

Safety And Reliability

ISO 26262 - The Relevance and Importance of Qualitative and Quantitative Methods for Safety and Reliability Issues Regarding the Automotive IndustrySafety and reliability are key issues of today's and future automotive developments, where the involved companies have to deal with increasing functionality and complexity of software-based car functions. New functionalities cannot only be found in the area of driver assistance - most of the new car functions are and will be safety related as for example in vehicle dynamics control or active and passive safety systems. The development and integration of those functions will strengthen the need of safe processes during the system development. The new upcoming automotive standard on functional safety (ISO 26262), which is derived from the generic functional safety standard IEC 61508 to comply with the specific needs to the application sector of E/E-systems in road vehicles, will provide guidance to avoid the increasing risks from systematic faults and random hardware faults by providing feasible processes and requirements. It is evident that aspects and methods of the safety and reliability engineering are implemented and suited methods are performed in the development process at an early stage. This is one of the requirements of the new ISO 26262, which introduces a so called automotive safety lifecycle to handle all those activities that are necessary to guarantee the functional safety of automotive E/E-systems. In the following, a brief overview of the upcoming automotive standard, its new safety life cycle and the connected activities in order to ensure functional safety for safety related systems will be given. The main aim of this paper is to show the relevance and importance of one of the major tasks within the ISO 26262: the process of the hazard analysis and risk assessment as it is currently performed in the automotive industry. With the help of an example from the automotive sector, the basic steps of this method to determine the automotive safety integrity level (ASIL) are explained. Depending on the ASIL, safety requirements need to be derived as a result of the new standard regarding safety integrity attributes. Furthermore, the connection of the automotive functional safety process with methods for qualification and quantification of safety and reliability issues will be explained in this paper. The Fault Tree Analysis will be used to exemplify one of these methods which are applied subsequent to the hazard analysis and risk assessment and which make a contribution to the validation and verification of the safety process.

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

Applied Sciences ◽

10.3390/app10217400 ◽

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.

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