Electronic Parking Brake(EPB) system is operated by Electronic Control unit(ECU). EPB system has been by replaced a traditional parking brake system, which is a mechanical device to be driven by a parking brake lever or foot pedal. EPB system is more convenient for the women and elderly. Interior design as well as space utilization has also been important recently. By using EPB system, it is possible to ensure more space in a vehicle. Also, EPB system provides better convenience and safety than the traditional system through the cooperative control of Electric Stability Program(ESP) or alone. In this paper, we propose methodology of software architecture design and function development for the EPB system based on software tools.