One of the biggest problems I have working on a number of large projects around NATS, is convincing some elements of the engineering world that the ATC requirement is king. Big mistakes were made in the NERc project as the shutters went up and fingers plugged ears, there is an element of that in the CASPIAN project - not in the ATC side though. Seriously, if you have any questions concerning this then there are groups of people at Swanwick that can answer your questions, or refer you to people who can. I agree that ATC Ops are NOT involved early enough but exactly when is a really difficult call.
If SACTA cannot interface with EFPS I will be stunned!
Can SACTA meet the ATC requirement? Time will tell. Same answer for delivering on time