1. A method for optimizing the performance of a configurable mobile communication system (MCS) in a multi-cell network, comprising: defining and encoding into a server that controls the performance of said MCS a plurality of self-optimizing network (SON) optimization functions for optimizing respective performance indicators of said MCS, wherein said SON optimization functions include at least a mobility robustness optimization (MRO) function, a mobility load balancing (MLB) function, and a coverage and capacity optimization (CCO) function; defining and encoding into said server a plurality of criteria classes in the form of an electronic criteria classes library that can be accessed by said plurality of SON optimization functions in said server, said criteria classes comprising data and instructions for identifying a set of candidate cells of said multi-cell network on which to carry out said SON optimization functions so as to improve the performance of said MCS; and defining and encoding into said server a rules-based function selector that selects a best subset of said SON optimization functions to be carried out in said candidate cells of said multi-cell network.