This paper describes the development of a fetch-and-carry robot to assist physically impaired people in an office environment. Different methods involving users are employed in the project, including the task analysis, Hi-Fi simulation trials and focus group sessions. Through an iterative design process, a prototype robot system has been developed, with an enhanced robot platform including a graphical user interface and natural language interface. The users' need for continuous feedback from the robot has led to the development of an animated character (CERO), which relates the two interface components and indicates the robot's current state by using simple gestures