Knowing what NAS does for us users, then I offer the following as its poor points.
1. Crap and unwieldy user interface which is not intuitive or forgiving of errors.
2. Inability to cope with any routes which are out of the ordinary. Everything has to be 'adapted' and I don't believe it has the capacity to cover every possible scenario which we see on a regular basis. Hence people spend an inordinate amount of time frigging the system and trying to get something meaningful out for controllers.
3. Extremely poor processing of direct routes, unable to provide the ATCO with anything meaningful except 7 or 8 irrelevant strips. Other FDPs can cope with airspace entry/exit which are not through recognised COPs. NAS apparently can't.
4. Defaults to 'preferred routes' between city pairs sometimes regardless of what the aircraft has actually filed. There is now a dependence placed on someone inputting the fact that the filed and processed routes differ. And if it is missed ...... ??
5. Far too many simple input errors seem to cause it to crash once a year or so. A decent system would have protections which provide a caution to the user before allowing them to make a critical error. Or simply just not allow them to do it.
6. Still unable to process PAC, REV and MAC messages thus involving staff in having to undergo co-ordination telephone calls everytime something changes after the ACT has been sent.
7. As already mentioned, extremely poor memory retention which means it needs to be shut down once a week .. is it running on a Sinclair Spectrum ZX81 or something ??
The above is a few minutes worth of thinking about, I am sure I could add many more little niggles, which I as a user have to put up with, and which I don't believe should be found in any modern and developed system, as could others.
My impression is that those who have worked tirelessy and thanklessly on the NAS 'empire' over the years now see a real threat to their domain and the realisation that their specialist knowledge and skills will soon become redundant. As such, they are extremely keen to champion NAS, some even propose developing it as part of any future system
I strongly agree the work done now and in the past has been done as well as it possibly can by a very skilled staff group, but one day we have to wake up to the fact that the core processing philosophy which NAS has was designed in an age which did not have any of the high traffic and complexity levels which we experience today. Sure, we have continuous tinkering with the system to add on bits and pieces, but that's not the same as providing a system which has it more or less right as its basic configuration. It's inflexible, it's not easy to use, and does not provide a simple or graphic interface capability.
Seeing some of the other systems out there and what they can do in simple mouse clicks or typed instructions, I for one won't shed a tear when the NAS system is thrown out to the Science Museum
