Photovoltaic (PV) energy is presently widely harnessed globally with the aim of mitigating atmospheric carbon footprint. Maintaining photovoltaic plant is therefore an important aspect of PV system management in order to achieve maximum generation throughout the generation horizon. Therefore, a novel preventive maintenance strategy was developed consisting of solar panels connected in series taking into account the influence of the panel production rate in this paper. The strategy proposes power energy forecast by ANN and then integrated into an analytical technique in order to simultaneously determine the optimal periodicity (T*) as well as the optimal number of panels (n*) to be replaced during each PM. The strategy also presents a systematic way of replacing the panels such that previously replaced panels during the previous maintenance are not replaced again within a particular replacement cycle. The model also evaluates and minimizes the total maintenance cost over the horizon to determine the optimal solution for the periodicity and number of panels to be replaced during each maintenance time.