The ISO 26262 standard de nes functional safety for automotive E/E systems. Since the publication of the rst edition of this standard in 2011, many di erent safety techniques complying to the ISO 26262 have been developed. However, it is not clear which parts and (sub-) phases of the standard are targeted by these techniques and which objectives of the standard are particularly addressed. Therefore, we carried out a gap analysis to identify gaps between the safety standard objectives of the part 3 till 7 and the existing techniques. In this paper the results of the gap analysis are presented such as we identi ed that there is a lack of mature tool support for the ASIL sub-phase and a need for a common platform for the entire product development cycle.
Development of innovative features such as advanced driver assistance systems
in modern day automobiles have led to an increased complexity in product
development and maintenance. This imposes an increased risk in terms of system
failure that could lead to unacceptable hazards. Thus it becomes crucial to
ensure functional safety. The ISO 26262 standard [
Most of the automotive companies have already started using safety analysis,
veri cation and validation techniques to ensure vehicle safety [
The introduction of the ISO 26262 functional safety standard provides more speci c development processes that help to avoid the hazards and threats in the development phases. Following steps should be taken to ensure compliance with the standard: a) The manufacturers should adopt the development processes; b) The manufacturers should determine the Automotive Safety Integrity Level (ASIL) for safety-critical systems; c) The manufacturers should satisfy the additional requirements.
The standardization process requires the consistency of methods, languages
and tools across all the sub-phases of the software lifecycle as well as system and
hardware development phases as stated in the section 5.4.4 of the ISO 26262 Part
6 [15, p. 4]. In recent years, safety related platforms such as OPENCOSS [
The remainder of the paper is organized as follows: In Section 2 we provide background information on the V-model of the ISO 26262 standard. In Section 3, we describe the systematic literature review process and the summary of the papers selected for the analysis. Section 4 presents the gap analysis results and Section 5 discusses the ndings. Finally, we present the concluding remarks and some related future works. 2
The safety standard ISO 26262 [
The ISO 26262 consists of ten parts as shown in Figure 1. Part 1, 2, and Part 8 to 10 are out of the scope of this paper, because Part 3 to Part 7 correspond to the safety life-cycle. The main part of ISO 26262 is structured based upon the V-model, as well as Part 5 and Part 6. Part 3 and Part 7 focus on the vehicle level. The main goal of Part 3 is to identify system hazards and risks through Hazard Analysis and Risk Assessment (HARA), then derive safety goals and Functional Safety Concepts (FSC) from them. Part 4 focuses on the system level. In this part, Technical Safety Requirements (TSR) are derived from FSC. Then system design can be carried out based on TSR. Part 5 and Part 6 focus on the subsystem/component level. In these two parts more detailed safety requirements are derived from TSR. Those safety requirements are assigned to the concrete subsystems or components for implementation.
In the following section, we present state-of-the-art techniques complying to
the ISO 26262 standard.
We use a Systematic Literature Review (SLR) methodology [
Peer-reviewed articles on the topics \ISO 26262" and \vehicle safety", published between 2008 and 2015, are included. We exclude duplicate reports of the same or similar studies as well as white papers are excluded. After the search and inclusion/exclusion processes, we identify 120 unique papers. In our ndings, we discover that higher number of papers are published in the concept phase (63 papers) than the development phases (51 papers) i.e., product development, software development, and hardware development phases of the ISO 26262 Vmodel. The remaining six papers are considered as general publications, since they cover all the phases of the V-model. To further narrow down the search results, citations are used as a key tool to assess the quality of the identi ed papers. Publications between 2013 and 2015 are included.
In the case of concept and product development phases, more than half of the papers have been cited at least once and number of papers cited more than ve are 18. Figure 2 shows the trend of papers published in each sub-phases from the selected sources. It can be inferred that the focus of the papers are more on the improvement of FSC (Functional Safety Concepts) in the conceptual phase and IVTA (Integration,Validation,Testing and Assessment) in the development phase. This shows the following observations: { More additional standardized procedures have been implemented from the IEC 61508 standard on the conceptual and development phases where automobile manufacturers required clear process for implementation. { Engineers and researchers were involved in the development of methodologies to ensure safety compliance of the system at these phases.
The summary of the selected papers mapped to the standard phases is presented in Table 1. Following section presents the gap analysis results between the ISO 26262 standard and the techniques identi ed from the selected papers. 4
A gap analysis helps to understand the shortcoming of existing approaches
suggested by literatures. The gap analysis is carried out between the ISO 26262
objectives of the Part 3 till Part 7 sub-phases.
i.e., Item De nition, Functional Safety Concept, and ASIL [
From the gap analysis of the product development phase, it is observed that there
are few tools [
Similar to the system architecture level, more techniques are used for the software
level [
In the case of hardware development phase, only few literatures are published
about the development required for the evaluation of safety violation. These
literatures provide techniques mainly to support two claims. One is hardware
architectural metrics and second is evaluation of safety goal violations.
Techniques like UML based meta-model [
Based on the gap analysis, the shortcoming and challenges of the techniques suggested by literature while ful lling the standard objectives are found. In the concept phase, gap analysis identi ed the lack of mature techniques that provide wider possible solutions for ASIL decomposition. It showcases the opportunity for integrating various techniques within the phase. For product development phase, gap analysis shows similar results. There are tools used for each sub phases of the product development but there is no common platform where all sub phase activities can be performed. This tool integration could facilitate the understanding and correct interpretation of the standard norms.
For the software and hardware development phase, same type of architecture description languages, such as EAST-ADL and AADL, are used. But there is a lack of common platform that supports both design and safety evaluations. 6
Since the ISO 26262 standard does not specify which techniques to be applied in ful lling the safety requirements, variety of techniques are developed for each phase of the ISO 26262 standard. However, a general overview of existing and emerging ISO 26262 related techniques is lacking. Therefore, in this paper, we carried out a gap analysis to identify the challenges and future trends to ful ll the ISO 26262 (part 3 to Part 7) safety objectives. We identi ed that the focus of research techniques is for the concept and product development phases. However, more techniques are needed for ful lling the objectives of the software and hardware phases.
As a future work, we plan to conduct similar study on the remaining phases of the ISO 26262 and develop a method for the software and hardware development phases. Furthermore, our analysis focused on the research results rather than the practical application of the standard. This requires further survey on the gap between research results and the practical applicability of the standard to re ect the actual situation in the automotive industry.