The evolution of renewable energy technologies over the years has contributed to expanding the exploitation of Hybrid Renewable Energy Systems (HRESs). In this work, a modelling framework for a hybrid wind/solar photovoltaic energy system with battery storage is proposed. The mathematical model provides quantitative decision support concerning the strategic design and operational management of HREss. The strategic design aspect, on the one hand, includes the number of components required in the hybrid system design, while the operational management on the other hand, refers to the integration of maintenance schedules during the operational phase while meeting the load demand for a customer base. The hybrid system comprises solar photovoltaic panels, wind turbines and energy storage. The objective is to minimise the total establishment cost of the system over a 20-year planning horizon.