The paper discusses a methodology to allocate functions to people and/or machines based upon the requirements of the tasks to be performed and the capabilities of each system. Although function allocation has been addressed within the human factors community for many years, the approach discussed offers two primary advances in the context of manufacturing and assembly systems. First, the state-of-the-art in automated systems, robotics, flexible manufacturing systems, methods analysis and human factors are integrated into a multi-disciplinary approach. Second, the methodology will provide manufacturing engineers with an easily understood procedure for assigning tasks to the appropriate system on cost/capability basis.