Abstract: Systems, methods, and computer-executable programs are provided for estimating margin in a network path. A method, according to one implementation, includes the step of executing a section-based analysis by estimating a margin parameter for each section of a plurality of sections forming a path through a network. The margin parameter is related to at least an available Optical Signal-to-Noise Ratio (OSNR) parameter and a Required OSNR (ROSNR) parameter. The method further includes the step of combining the estimated margin parameters for the plurality of sections to obtain a section-based estimate. In response to determining that the section-based estimate falls outside an acceptable confidence range, the method includes executing an additional path-based analysis to modify the estimate of the margin parameter.