Although many projects themselves have overrun, or have been over budget, there is another probable cause for the massive debt that the procurement system is now in - Manpower costs.
One specific IPT I'm aware of reorganized several years ago under one of the various rationalization progs and was reduced by approx 40%, the work was federated to other IPTs (or so they were promised) and their mandate was to manage in-service equipment only! However, this tied in with the HERRICK push and the work didn't reduce as was predicted, moreover it increased in line with the massive jump in UORs. So having made the savings, they were unable to support the frontline, and after much deliberation they were given the nod to import contractors. The snag is, that was 4 years ago, and as you have probably guessed many of the contractors are still there! (Min fee ........£450 per contractor per day!!)
So with this being a relatively small IPT, it would be interesting to see the total cost of contractors for DE&S for the period of the last gov.....?