fredag den 15. august 2008

When is the Assessor independent?

The Assessor should be independent from the Supplier and Customer of the product. The needed "Degree of economical and organizational Independency" is decided by the Safety Authority.

As it can be seen above, from Figure 6 in EN50129:2003, the Assessor can not be a part of the same organisation, in which the Project Manager, Designer, Implementer, Verifier or Validator belongs.


The idea of complete "independence" should be substituted with the more flexible concept: "The degree of economical and organizational independence". This concept can furthermore be simplified in to whether it should be in-house or external assessment.

The in-house assessment-divisions are - due to historical reasons - organizations placed inside the large suppliers e.g. Siemens, Bombardier, Alstohm, Alcatel. Because they are organizations inside the suppliers, they have a low "degree of economical and organizational independence". Nevertheless, the Safety Authorities often allows these divisions as Assessors, because they trust the in-house assessment:
  1. The in-house assessment-divisions have a high technical knowledge of the products,
  2. the entire reputation of the companies depend on their integrity and
  3. the alternative external Assessor-companies are just the same paid by the suppliers, which undermines their independence.
External assessment can be performed by inspection companies like DNV, Lloyds and Tüv, which have a high degree of economical and organizational independency, because they do not have any shareholders, but are owned by a foundation.
Another alternative could be the Advisors like Atkins, which have shareholders, but still have a high degree of economical and organizational independence from the traditionally railway Suppliers, Infrastructure owners and Operators.

As a guideline to the minimum needed degree of independence the following criteria can be used: What is the SIL-level of the products safety functions? And how complex is the Project? This interpretation is shown in the table below.

For SIL1/2 or simple projects, the degree of independence it not so important for the safety. In these cases it is often more convenient (faster, less paperwork) with in-house assessment.
For SIL 3/4 and complex projects, it is necessary with a high degree of independence for safety reasons and external Assessors from Assessor-companies should be involved.

Next chapter >> 5.3 Competence of the Assessor?

Focus on the source (/TR 50126/, "Guide to EN 50126")

In TR 50129 ("guide to EN50129") Draft 2006, chapter 7.1.2, is the word "Organization" interpreted to either an external organization or an autonomous in-house organization:

"In general the Safety Assessor or the Safety Assessment Organisation must be accepted by the safety authority. The safety Assessor could be either a member of the in-house organisation (e.g. Assessment Centre) or an independent external organisation. The degree of the independence of the Assessor from the development and RAMS Process must be proven and accepted by the safety authority in charge of the approval. The Assessment organisation should have an accreditation in accordance with EN 45004.

(The mentioned standard EN 45004 contains some requirements to an in-house department regarding economical and organizational independence from the other departments and some professional skills to the Head of the department.)

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