Pump Scheduling for Water Supply Production using Mathematical Programming

This research proposes a mathematical model and a solution for a pump scheduling problem applied in a water supply production plant of the Provincial Waterworks Authority so that the minimum electricity cost is achieved. The branch and cut algorithm in OpenSolver is used to solve the problem. Five pump scheduling scenarios are studied. In the first scenario, the pump scheduling program is implemented in the present production system without production condition changes. In the other scenarios, four main factors are adjusted to analyze the effect on the electricity cost. These factors are the minimum volume of water in a clear water tank, the stock of finished water, the piping capacity, and water demand. The results of the first scenario show that the proposed pump schedules can reduce the electricity cost by 7.87%. The results of the other scenarios indicate that all main factors, except the capacity of the pipe line affect the pump schedules and the electricity cost. The experimental results of these four scenarios yield significant information in regard to production system improvement.