Mathematical modeling is the process of using various mathematical structures such as graphs, equations, diagrams, scatterplots, and tree diagram to represent real world situations (Annenberg Foundation, 2017). For instance, mathematical modeling may be employed in business production. With this, the researcher aimed to determine the optimum profit of PSAU Water Purifying Facility through mathematical modeling. The study used descriptive-expository type of research in achieving and discussing the results in understandable and clearly way. The mathematical modeling of the production of PSAU Water Purifying Facility aimed to solve the optimum solution based on the traditional solving and the objective function that maximizes the profit of the PSAU water purifying facility. The mathematical modeling was completed through the use of Excel Solver and AMPL Program. Based on the results, the researcher set a new production of different sizes of bottles that will increase or maximize the profit of the PSAU Water Purifying Facility. As a recommendation the other researchers may use other programming language to find the optimum solution. Also, other researchers may implement the model in the water facility of the PSAU to see if it is effective or not.