Confirmation Review vs Verification Review, Decoding the puzzle

The ISO 26262 series of standard is an international standard for functional safety in road vehicles (except mopeds) developed by International Standard Organization (ISO). The development of road vehicles involves many levels of development stages which can be tailored as per the unique design of vehicle. The standard doesn’t give a straight forward but a structured way of safety product lifecycle development activities.

The general product safety design lifecycle includes the following stages Concept-Design-Development-Verification-Validation. In this blog, we will focus on how ISO26262:2018 work products undergo the verification process, that includes confirmation measures and verification review. First, let's understand how ISO 26262 integrates these activities into the product safety design lifecycle.

Product Safety Design Lifecycle

The ISO 26262:2018 series of standard is divided into total 12 parts, wherein part 2 to part 9 are focused on the safety product lifecycle development of road vehicles with the respective requirements (termed as work products) to be achieved during the development. To show the completion of the specified requirements, the ISO 26262 introduces the term confirmation measures. The standard states that the confirmation measures are performed to judge the functional safety achieved by the item, or the contribution to the achievement of functional safety.

The safety manager is responsible for scheduling the confirmation measures. The details of a confirmation measure are planned by the person responsible for the respective measure. The confirmation measures consist of a confirmation review, an audit and an assessment concerning functional safety and are defined as:

1. Confirmation Review: Confirmation that a work product provides sufficient and convincing evidence of their contribution to the achievement of functional safety considering the corresponding objectives and requirements of ISO 26262

2. Functional Safety Audit: Examination of an implemented process with regard to the process objectives of ISO 26262

3. Functional Safety Assessment: Examination of whether a characteristic of an item or element achieves the ISO 26262 objectives

Table 1 in ISO26262:2018 Part 2 clause 6.4.9 provides the list of confirmation measures with the corresponding independence level as per ASIL level. The following table showcases the confirmation measures:

S No.	Description
1	Confirmation review of the impact analysis at the item level
2	Confirmation review of the HARA
3	Confirmation review of the safety plan
4	Confirmation review of the Functional Safety Concept
5	Confirmation review of the Technical Safety Concept
6	Confirmation review of the integration and test strategy
7	Confirmation review of the safety validation specification
8	Confirmation review of the safety analyses and the dependent failure analyses
9	Confirmation review of the safety case
10	Functional Safety Audit
11	Functional Safety Assessment

The notation of level of independence are as follows:

• "—": no requirement and no recommendation for or against regarding this confirmation measure;

• "I0": the confirmation measure should be performed; however, if the confirmation measure is performed, it shall be performed by a different person in relation to the person(s) responsible for the creation of the considered work product(s);

• "I1": the confirmation measure shall be performed, by a different person in relation to the person(s) responsible for the creation of the considered work product(s);

• "I2": the confirmation measure shall be performed, by a person who is independent from the team that is responsible for the creation of the considered work product(s), i.e. by a person not reporting to the same direct superior; and

• "I3": the confirmation measure shall be performed by a person who is independent, regarding management, resources and release authority, from the department responsible for the creation of the considered work product(s).

Here, a question emerges- What exactly constitutes a confirmation review, and how does it distinguish itself from a verification review? Let's delve into the description provided by ISO 26262:2018 to clarify the concept of confirmation review.

Confirmation Review

Confirmation review is meant to provide evidence that the work product adheres to the requirements of the ISO 26262. The confirmation review is carried out for the 9 key work products as mentioned in the section above with the level of independence as per ASIL level. To increase confidence in the achievement of the review objectives, the reviewer checks the correctness, completeness, consistency, adequacy and contents of the work product against the corresponding ISO 26262 requirement.

The confirmation review of the work product which is under the scope of the safety plan needs to be completed before release for production report. Now that we've covered what the confirmation review entails, according to ISO 26262:2018, let's take a look at what exactly the verification review involves.

Verification Review

As per the general understanding in the product design horizon, the verification review is conducted to check the compliance of the design as per the stated project/customer requirements. The ISO 26262 defines verification review as “verification activity to ensure that the result of a development activity fulfils the project requirements, or technical requirements, or both”. The stated goal of verification review is technical correctness and completeness of the item or element.

According to ISO 26262:2018, section 8, clause 9.4.3.2, the verification review requires evaluation by a different individual than the author(s) of the work product being verified. It is clear that verification reviewer’s independence level is not governed by the ASIL level of the item/element. When comparing the independence level of verification reviewer and of confirmation reviewer, it can be stated that it represents I0/I1 level of independence.

To make it easier, we have listed the respective work products which require verification review as per ISO 26262:2018, and are as follows:  

It can be noted that some of the work products are same as of confirmation review. Therefore, the question arises: Can we merge the confirmation and verification reviews of these work products, and if so, how?

Decoding the Puzzle

It's essential to grasp the distinction between confirmation and verification reviews when contemplating merging review activities. Equally important is determining whether ISO 26262 permits this consolidation. To make things clear, ISO 26262:2018 part 2 clause 6.4.10.5 states that “A confirmation review and a verification review may be combined, provided the review is performed with sufficient independence in accordance with Table 1 in part 2”.

What does this actually mean and how can we do that? The standard doesn’t explain any process or way of doing it. Based on our comprehension of the statements, let's delineate the scope of both verification and confirmation reviews.

The scope of confirmation review is to make sure that the work product adheres to the requirement of the ISO 26262 series of standard whereas, the scope of the verification review envelopes the project requirement, technical requirement or both.

But how to combine?

But the challenge over here is, the verification review only has the independence level I0/I1 whereas the independence level of confirmation review depends upon the ASIL level.

The management of the organization over here can take a decision if they want to have only 1 review activity, they can inculcate the confirmation review requirements under verification review for the respective ASIL level. This will help the organization avoid the duplication of the following work products review:

1. Hazard Analysis and Risk Assessment (HARA)

2. Functional Safety Concept

3. Technical Safety Concept

4. Safety Analyses and the Dependent Failure Analyses

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I hope this article helps individuals and organisations involved in ISO 26262 implementation in comprehending the distinction between confirmation and verification reviews and provides guidance on incorporating both terminologies into their development projects.

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