The invention provides a method, system, and program product for
determining a gradient of a parametric yield of an integrated circuit
with respect to parameters of a delay of an edge of a timing graph of the
circuit. A first aspect of the invention provides a method for
determining a gradient of a parametric yield of an integrated circuit
with respect to parameters of a delay of an edge of a timing graph of the
circuit, the method comprising: conducting a statistical timing analysis;
expressing a statistical circuit delay in terms of a delay of the edge;
and computing a gradient of the statistical circuit delay with respect to
parameters of the delay of the edge.