This paper considers a centralized supply chain with consignment inventory (CI) system, where a vendor keeps a finished product and supplies it at the same price to multiple buyers. CI is a process where the buyer pays with delay for the goods supplied by the vendor. Considering the time value of money, this study compares two types of delay in payment in CI, which have been rarely considered (real use and order to order). Furthermore, two different metaheuristic algorithms, genetic algorithm (GA) and a hybrid algorithm, containing GA and particle swarm optimization algorithm, are used to maximize the supply chain net profit and calculate the proper values. Finally, a sensitivity analysis is performed to examine the effects of each parameter on the total net profit. Moreover, by applying a paired t-test, a comparison is made between two types of CI system and also between GA and the hybrid algorithm.