Fully flexible assembly systems (F-FAS): a new concept in flexible automation

Purpose - Flexible automated assembly is an emerging need in several industries. The purpose of this paper is to address the introduction of an innovative concept in flexible assembly: the fully flexible assembly system (F-FAS). Design/methodology/approach - After an analysis of the state of the art, the authors describe the proposed F-FAS, from a layout, constitutional elements, functioning principles and working cycle point of view. Second, the authors compare the traditional FAS and the manual assembly system versus the proposed F-FAS according to their throughput and unit production costs, deriving a convenience map as a function of the number of components used in assembly and of the efficiency of the F-FAS. Finally, using a prototype work cell developed at the Robotics Laboratory of University of Padua, the authors validate the F-FAS concept. Findings - Results of the research indicate that the concept of full-flexibility can be exploited to bring automation to a domain where traditional FAS are not competitive versus manual assembly. In fact, the F-FAS outperforms both traditional FAS and manual assembly, in terms of unit direct production costs, when the size of the batch is small, the number of components used in assembly is large and the efficiency of the F-FAS is reasonably high. The F-FAS prototype demonstrated the possibility of working, for certain conditions (models/components/production mix), in the F-FAS convenience area, highlighting the achievable cost reduction versus traditional assembly systems. Originality/value - The novelty of the study lies in the F-FAS concept, its performances in terms of flexibility, compactness, throughput and unit direct production costs. A prototype work cell validated the concept and demonstrated its viability versus traditional assembly systems, thanks to convenience analysis.