The real problem isn't the IT system as such (it's pretty terrible, but not to the extent that it stops you working). The problem is the processes. We can have a potential soldier in front of us who we've interviewed and decided we want, with his medical form filled in by his GP who has passed a fitness test but it will still take a couple of months minimum to actually get him in the Army. That's best case, worst case is a year plus.
Maybe they could do with a few more solution architects or whatever, someone who can take a look at not just what the best way to accomplish a series of tasks is but at why we are doing them at all.