The primary cause of cost overruns with machined parts is poor specification. A part can be under-specified, as often happens when a badly worn out part is presented and the machine shop is asked to “make one just the same, but without the broken bits”. At the other end of the scale is the beautifully drawn part with all the standards and all the tolerances and all ground and polished surface finishes. There is a sweet spot somewhere in between. This is where the requirements