CCIA
Hi Roffa,
Indeed they have, it's called the CCIA (I forget what that stands for!) The program will look at your schedule and your proposed callsigns, and identify potential confusion incidents based on callsign similarity. Where it identifies a potential for confusion, the software will suggest a 'safe' alternative callsign.
It's not a bad bit of software, and it's nice to see NATS being proactive, but unfortunately it will only consider your own airline's schedule, and it will only look at deconflicting flights within UK airspace. Of course, the program can only consider the scheduled departure/arrival time, and although there's a buffer of a few hours included there may be unidentified confusion incidents when things get seriously off schedule.
For these reasons in reality its usefulness is pretty limited and it does nothing to solve the problem of inter-airline callsign confusion, or confusion outside of the UK.
Eurotraveller