Re: Optional
"why integrate a system into another system when the first system is no longer going to be used"
There's not going to be one day where they switch off AirWave, and everyone starts using ESN. It's going to be a gradual process, probably with small groups switching over piecemeal (and probably some switching back, and the usual hold-outs refusing to touch the new system until their managers physically take it off them etc. etc.). The upshot of this is that both systems are going to have to run alongside each other for a period of time, and looking at the process so far, that period of time is probably going to be measured in years, if not decades.
"Common sense says you just[....]"
This is a government project, what is this 'common sense' of which you speak?