Evaluating Skill-Based Control Architecture for Flexible Automation Systems

For the manufacturing of customized products, systems require easier and better adaptivity of the production plant especially in terms of the control software. In recent research projects, a skill-based architecture has been introduced and presented within an industrial demonstrator proposing the required adaptivity. Within this work, the skill-based architecture is compared to a more traditional component-based hierarchical approach to identify strength and weakness of this approach, which then enables further improvements of the skill-based architecture. The flexibility of control software can not directly be measured. Therefore execution time, modularity, readability, and reusability considering the impact of component exchanges are used as evaluation criteria. Modularity and reusability are measured by the number of needed Function Blocks (FBs) and that can also be used for other systems respectively. To evaluate readability three derived metrics from the basic Halstead Metric are used. The comparison shows that the skill-based architecture is more complex but much more flexible than the more traditional component-based hierarchical approach.