Process network synthesis (PNS) is a method to represent a process structure in a directed bipartite graph. Process network synthesis uses the P-graph method to create a process structure. The scientific aim of this method is to find optimum structures.
Process network synthesis uses a bipartite graph method P-graph and employs combinatorial rules to find all feasible network solutions (maximum structure) and links raw materials to desired products related to the given problem. With a branch and bound optimisation routine and by defining the target value an optimum structure can be generated that optimises a chosen target function. 
Process Network Synthesis was originally developed to solve chemical process engineering processes. Target value as well as the structure can be changed depending on the field of application. Thus many more fields of application followed.