1. A method comprising: defining a circuit as a plurality of sub-circuits; defining a set of one or more source parameters for each sub-circuit of the plurality of sub-circuits; executing a respective circuit simulation on each set of source parameters; executing a respective Stochastic Analysis Process (SAP) analysis on a result set of each respective circuit simulation; integrating the results of each respective SAP analysis step to generate an integrated result data set; performing a single circuit simulation step on the integrated result data set to generate an integrated simulated data set; and performing a final SAP analysis on the integrated simulated data set to generate a final simulation result; wherein the SAP analysis comprises receiving an input distribution of one or more parameters of a pre-defined system and mutual correlations between the parameters; normalizing the parameter distributions and decomposing the mutual correlations to generate standardized independent parameter sets; generating a specific set of input values for sampling of the pre-defined system based on the standardized independent parameter sets; performing pre-defined system sampling on the specific set of input values to generate pre-defined system output values; performing orthogonal polynomial fitting on the specific set of input values, the predefined system output values, and the standardized independent parameter set to generate an SAP model; and using the SAP model to generate an output distribution of the pre-defined system output, wherein the system output is a statistical representation of the output distribution of the pre-defined system based on variation of the input parameters, and wherein the statistical representation comprises a Cumulated Distribution Function (CDF) set.