The research and development of energy optimization methodologies in parallel pumping systems in recent years have aimed to impact operational costs, energy savings, and system reliability.Operational costs are correlated with the number of units operating simultaneously, considering power demand, operating point, and system reliability.Additionally, the optimization strategy must manage the operation of pumping units by regulating the output flow according to process dynamics and the energy tariff structure.In this document, an energy optimization model is presented for parallel pumping systems operating under variable demand conditions.The optimization problem is addressed through an iterative constraint-based analysis model, capable of predicting the number of units that should operate simultaneously and their corresponding speeds during future time intervals.The methodology suggests analyzing system operation indicators as inputs for the prediction model.The effectiveness of the methodological strategy for optimal dispatching of parallel pumping units is verified in a utility sector pumping system.The results obtained demonstrate savings between 20% and 25% in energy costs for system operation, which represents a contribution in the search for a significant use of energy and energy sustainability.