I am firmly of the opinion that to cost a programme, the customer must first state his requirement and quantify it. This has not been Service policy since January 1988; at which point MoD(PE) was told to DIY. Nothing had changed by the time I retired. Unless the PE/DPA/DLO/DE&S project office had someone who'd done that job in the Service HQ (and in aviation we're talking about a slack handful of people per Service), then everything was a honking great wet finger. First things first.