Product Approvals

[PJD]

Hi all, 
Does anyone know a good source of info for the Product Approval process which would be applied to signalling products?

[Jerry1237]

Search the Internet for Network Rail Product Acceptance. For approval, that is generally internal to the organisation you work for.

What information are you seeking?

Note: there is a significant difference between approval and acceptance!

[PJD]

Hi Jerry,
I am looking for the 'what' and 'why' - what one would need to do for a product to be used in a signalling application and why one would need to do it.
I guess a safety case would be the basis of this, but at the moment it is just a guess.
Hhhhmmmm, maybe I am looking for acceptance?! is approval a NR thing? ie approved for their infrastructure? In that case what is acceptance?

[Jerry1237]

NR rarely approve anything, design being a perfect example of NR acceptance whereas a CRE approves it. Acceptance, in this case, is NR accepting the design is correct based on statements made and assurances given by the designing party and do not wish to take ownership/responsibility for it. That would be approval of the design.

Why products are accepted is simple. When a product has been demonstrated to be fit for purpose, to be reliable, work in the correct environment and not cause negative effects to other equipment/personnel, the risk of that product being used, especially in safety critical applications, is severely reduced. An infrastructure owner would also wish to ensure the product is replaceable (repair and/or obsolescence), maintainable and is limited to suitable applications.

Not necessarily a safety case. It depends on the equipment being proposed. A SIL4 Interlocking is a very different consideration to a fuse built to applicable standards. It also depends if the equipment is novel, the application is novel [for the equipment or to the infrastructure], grandfather rights or whether there is cross-acceptance.

With NR, the initial application lists all the above and permits a list of requirements to be provided. These then require a demonstration of how they are met and dependant upon the equipment, acceptance could be given, further information requested or a trial.

The NR PA website is very useful and there is plenty of information to digest.

[PJD]

Great, thanks.
Lets dig into the SIL4 interlocking example a little.
I have a PLC from Maplins, I think I can use it to control a signals and points and save NR £££££, where do I start?

Obviously this in tongue in check, but you get my drift?!

[Jerry1237]

Read the website, the process is quite simple. The requirements can be quite complex.

For your Maplins Interlocking... can you demonstrate EMC, that it is SIL4, the environmental requirements beyond EMC/I such as temperature range, power draw, that it operates reliably with high availability, does it comply with all relevant company standards, railway standards, UK law, international law... How do you manage configuration, testing, V&V.... Define the business case for the cost savings you refer too and the number of installations expected. Fill out the NR application (don't submit obviously!) and see how far you get.

[Jerry1237]

NR/L2/RSE/100/05 currently at Issue 3.