Process-network synthesis was originally introduced for conceptual process design. However, recent developments extend the capabilities of the P-graph framework to consider such time constraints in process-network synthesis that mainly arise in process operation. The current paper shows how to formulate and solve process scheduling as time constraint process synthesis, i.e., how to synthesize the optimal process schedule. Multiple classes of classical scheduling problems are revisited and reformulated. Algorithm is proposed for generating superstructure involving each candidate schedule in a way that the operating units are regarded as resources and changeovers as potential steps of the process. Various storage policies are incorporated. The differences of the storage policies are graphically highlighted both in the superstructures and in the solutions. The mathematical model constructed and analyzed, integrates the variables and constraints related to process synthesis, as well as, a precedence based formulation of the time constraints.