1. A computerized method for management optimization of pressurized liquid distribution networks performed by a processor, comprising: receiving via a input interface in communication with said processor, a network model representing a real physical pressurized liquid distribution network comprising a plurality of network elements including pipes, tanks, valves, and pumps, said network model having a plurality of liquid flow variables and a plurality of variables describing physical properties of each of said network elements; performing as part of a global optimization phase: simulating, by said processor, said network model by solving a plurality of non-linear mathematical equations representing the behavior of said plurality of liquid flow variables, thereby generating at least one result set comprising at least one result value for each of said plurality of liquid flow variables; feeding said at least one result set to said plurality of non-linear mathematical equations; linearizing, by said processor, said plurality of non-linear mathematical equations; receiving, via said input interface, a plurality of network model optimization requirements from a user; optimizing, by said processor, linearized said plurality of mathematical equations according to received said plurality of network model optimization requirements, thereby generating at least one global optimized solution for linearized said plurality of mathematical equations; performing as part of a local search phase: performing, by said processor, a local search starting from said at least one global optimized solution using a simulator simulating said network model by solving said plurality of non-linear mathematical equations representing the behavior of said plurality of liquid flow variables, thereby generating at least one locally improved solution; wherein said at least one locally improved solution includes desired states of said network elements of said real physical pressurized liquid distribution network.