Implementing ISO 26262 Together with SOTIF

 

ISO 21448 (SOTIF) is currently in a committee draft (CD) form and work is underway to become a DIS later this year. Although many SOTIF processes can be aligned with corresponding ISO 26262 processes, there are unique SOTIF processes such as functional modifications to reduce risk and functional safety assessment. Several issues involving the joint implementation of ISO 26262 and SOTIF will be discussed.

 

This article discusses in detail the below listed points:

• Ø  Introduction
• Ø  Necessity of SOTIF
• Ø  Integrated Implementation Strategy
• Ø  Synergies & interactions
• Ø  Implementation issues
• Ø  Use Case – Lidar based perception system

Ø  ISO 26262 aspects

Ø  SOTIF aspects

 

Additional learning features from the article:

Ø  ASIL – Automotive Safety Integrity Levels

Ø  HARA – Hazard Analysis and Risk Assessment

Ø  The V shaped slide – FuSa Scheme

The article also discusses about malfunctioning in the automotive vehicles.

 

ISO 26262

There are many perception of components in today’s automotive vehicles, that are electronic and also software. On the other hand, we have the malfunctioning which could be hardware or software. ISO 26262 is all about malfunctioning behaviour of these particular elements. These particular standards talk about Functional safety at the technical level in terms of basic functionality and requirements.

 

ISO 26262:2018 FuSa Scheme

Ø  ISO 26262 deals with preventing Hazards (events leading to human injury) due to malfunctioning of the intended functions of the item. Consequently, the identification and implementation of Functional Safety need of an autonomous driver implemented vehicle would follow the scheme provided in the standard.

Ø  Determine the vehicle level functional safety needs

·         Identify the basic functions and requirements (Item Definition) and related preliminary architecture

·         Derive possible malfunctions

·         Identify operational situations which could lead to hazards for the malfunctions

·         Identify the probable hazards and classify their related ASILs

·         Develop safety goals encompassing all the hazards with non-QM classifications.

 

 

Learning the V Model

1.      We begin with item definition and have the HARA where we identify all the hazards and risk assessments and based on that we decide what to do – in most cases we need to follow the process.

2.      We can go as per the process which are safety goals and specify the requirements from there.

3.      Then comes the Functional safety concept which is a major activity.

4.      Next is laying out all the detailed requirements of the system and that would lead you to the architectural requirements.

5.      At the bottom of the V is the hardware and the software.

6.      The right side of the V is mostly concerned about testing, verification and validation.

7.      So we begin with Unit testing at the very bottom going upwards to integration testing, then to verification activities and finally validation that has to be done at the vehicle level. These activities follow a certain number of processes that are laid down in certain standards.