Project Lifecycle- summary of NR GRIP process

[PJW]

Network Rail uses a document called Guide to Railway Investment Projects to define the various project stages and, at least in theory, permit work to start on a later stage until the previous one is complete. In reality large projects sometimes need to be split up (as it is not always possible for development and implementation to be entirely synchronsied between different areas / disciplines).
The attachment summaries pictorially.