The application of the hopper as a potential candidate model for the ship-based transport system of natural gas hydrate has become a significant interest in the ship-building research community. We propose and provide a design guideline for a hopper system by exploring the effects of the outlet size and hopper angle on the discharging speed of ball-type pellets. Here, the response surface method (RSM) is adopted to find the optimum condition and key factors that influence the discharge time of a hopper system for limited sets of experiments. Three different cases of hopper discharge are investigated, i.e., two of them with different size pellets, each, and one with mixture of the two sizes. The designed set of experiments with RSM allows visual representation of each factor affecting the response value or discharge speed and the effects of the outlet size and hopper angle. As a result, a mathematical model and the correlation factor for hopper design parameters can be found to determine the pellet discharge speed.