stating ISA Question in the header. Your name will not appear on the website. The Group will try to answer as many of your questions as possible, and will place answers on the website. If you do not wish your question/answer to be placed on the website, please state this when submitting your question.

Q - What are ISAs used for?

ISAs objectively assess the safety aspects of a process, system or organisation. From the evidence gathered in the assessment the ISA forms a judgement on whether the safety requirements have been met. The ISA may use techniques such as auditing, analysis, interview, review or witness testing to gather the required evidence. See also the definition of the ISA function.

Q - Can an ISA be involved directly with a project for example help write the safety case?

It is not recommended and should be avoided. Any direct involvement with a safety product could compromises the independence of the ISA. The pitfalls of advice are summarised in the ISA Guidelines for MOD Projects, which states:

"Suppliers and IPTs (the supplier's customer) often need in-depth independent safety advice, particularly if the ISA identifies an evidence shortfall, in what safety processes can provide the necessary additional evidence. Such advice can compromise the ISA as they then have an interest in the success of the advice. Therefore it is best to provide independent safety consultants for advice rather than the appointed ISA. Clearly, it would be the ISA's responsibility to identify areas of weakness and evidence shortfall in the safety argument."

Furthermore, any advice an ISA gives should be documented so that the context of the advice is understood.

Q - What is the scope of the ISA's task and how deep is their involvement, for example does he/she have to do witness testing?

The ISA should assess the safety product evidence so that he/she is sufficiently confident to make a clear statement that the safety requirements have or will be met. This clear statement may be an endorsement of the safety case or some other clear stamp of approval.

The severity of the hazard or the safety risk of the project determines the depth of the ISA role. For example the ISA may judge that witnessing the testing of a particular safety property with high risk or severe consequence is essential to establishing his/her confidence in the evidence. However, witnessing the testing would be only one part of the evidence that the ISA may examine in order to come to a judgement on the veracity of a particular test. The ISA may expend analysis and assessment effort reviewing the test objectives, specification and test environment. The International standard EN 61508 gives little guidance on the extent of ISA involvement but does make strong recommendations on the degree of independence and defining the scope of the assessment. The depth of assessment should be agreed with the customer and the ISA.

Q - What is an ISA?

The definition agreed by the ISA Working Party.

Q- How do I contact an ISA?

Currently there is no central list of ISAs.  A web search for the term 'ISA' will NOT be helpful!  A web search for 'Functional Safety' provides a list of some potential companies BUT has some notable omissions.  The Professional Institutions may also have lists of their members active in the field. The Safety Critical Systems Club has some relevant links. The BSI may be able to provide contact details of individuals/organisations active in standards work. 

A further route is to contact procuring organisations for their recommendations.  Further details will be added later.

Q - Do I need an ISA?

Reasons for employing an ISA.

Q - Do I need Safety Assurance?

The reasons for needing safety assurance.

Q - How do I become an ISA?

To be answered.

Q - What competencies are required?

A good starting point is to read the IET/BCS Competency guidelines "Safety Competency and Commitment". 
 
To purchase the book see Publishing for details.

Q - What are the liabilities?

A thorny question, open to much debate.