The integration of renewable energy resources (RER) into an existing distribution system is an important topic in dealing with energy challenge the world is facing. With rapid development of electric energy storage (EES) technologies, there is a growing interest in integrating both EES and RER into power systems to improve their reliability and economy. In this paper, the adequacy and economy of distribution systems integrated with both EES and RER are assessed. A novel model predictive control (MPC)-based operation strategy is presented to minimize distribution system energy purchasing cost by coordinating multiple power supplies from EES, RER and external grid. An islanding operation is implemented to improve the distribution system reliability and reduce customer interruption cost. A reliability and economy assessment framework based on sequential Monte Carlo method integrated with the MPC-based operation and islanding operation is proposed. Case studies are conducted to demonstrate the reliability and economy improvement by implementing the proposed operation strategies together with integration of EES and RER, and also investigate how EES capacity, power limit, and wind turbine generation capacity affect system reliability and economy.