Element A is comprised of components X and Y.
Nominal Estimation:
C(A) = C(X) + C(Y)
C(z)  cost of Z.
MonteCarlo:
X and Y are each associated with the cost frequency curve.
A computer picks a random value for X and for Y subject to their
respective cost frequency curves. These two values are added to form a
value for the cost of A.
The former step is repeated sufficient times for these value to
establish a histogram that may be translated into a cost frequency
curve for A.
The cost frequency for A is evaluated to C(A).
