Service robot is a complex system, which demands a highly flexible, extensible, and maintainable software architecture framework to achieve its goals/tasks. This paper describes a software architecture framework designed to fulfill these needs. To date, the architecture has been successfully applied to the development of different service robots; Olivia, Mika and Lucas developed by A*STAR Social Robotics Laboratory (ASORO). These service robots have different hardware and software requirements and are exhibited in various events, including RoboCup 2010, World Cities Summit and TechFest 2010. During the course of these events, these robots successfully demonstrated the functionality of the software architecture that seamlessly integrates various robotics components in completing a challenging real-world task. Most significantly, the architecture demonstrated its flexibility, extensibility, and maintainability to different domains. These outcomes indicate that the architecture has potential to contribute towards the long term goal of intelligent service robotics in different service domains.