Multi-level skill-based allocation methodology for evolvable assembly systems

Manufacturing systems are under constant pressure to deliver in an agile way high-quality products, hence, assembly systems are required to be flexible, adaptable and reconfigurable to cater for these trends. This has led to the rise of new paradigms, where concepts such as, plug and produce, modularity and agent technology are applied. Among them highlights Evolvable Assembly Systems (EAS) which proposes an agile solution by considering a plug and produce environment. This approach presents a number of opportunities and challenges. One of these is the allocation of assembly capabilities to process requirements. This arises due to the separation of product driven requirements from the implementation process, into capabilities that embed the concepts of modularity and plug and produce. Users tend to define assembly process requirements at a high level, with the objective to be equipment independent, while equipment specific processes are normally defined at the lowest-level of granularity to be applied in different assembly workflows. The more specific a user defines production requirements the more limited is the number of solutions that can be offered by a particular assembly system, hence, the tendency to define production requirements at high level. This presents an important problem, the need to bridge the gap between assembly process requirements definition with the lower-level capabilities provided by equipment in a particular assembly system. This scenario is the motivation of this work, and the definition of a methodology that takes into consideration different levels of process requirements definitions, and the allocation of lower level skills (capabilities) which are equipment specific using skill-based patterns to provide feasible assembly processes solutions.