scope:

This Guidance Note provides an insight into significant SSI program and data problems that have been found on Network Rail's Signalling Infrastructure, together with their effect, their history and how they have been addressed; further detail and guidance is contained in SSI8000 "SSI Applications Manual", the contents of which are detailed in NR/L2/SIG/17002. Guidance on whether any solutions should be applied retrospectively is outside the scope of this Guidance Note.

Purpose

This Guidance Note summarises significant SSI program and data problems identified on Network Rail's Signalling Infrastructure, and adopted solutions, to assist Engineers in identifying and avoiding them wherever possible.