Modelling and Optimization of Fully Flexible Assembly Systems (F-FAS)

Purpose - The paper aims to address the modelling and optimization of fully flexible assembly systems (F-FAS), a new concept in flexible automation recently introduced by the authors. Design/methodology/approach - The paper presents a mathematical model of the F-FAS, which makes it possible to predict its efficiency, throughput and unit direct production costs, correlating such values with system and production variables. The mathematical model proposed in the paper was derived from experimental and simulation data, which were analysed for a wide range of different productions and system settings. Findings - Correlation analysis revealed that there are three main determinants of the efficiency of the F-FAS: the number of components (types of parts) used to assemble the models (production variable); the average complexity of the models to be assembled (production variable); the ratio of the average perimeter of components (production variable) over a significant dimension of the working plane (system variable). Such parameters makes it possible to estimate the maximum attainable efficiency of the F-FAS, and to calculate the optimal setting of the feeder which makes it possible to obtain such efficiency during the execution of the whole production order. Originality/value - The model presented in the paper makes it possible to quantify in advance the real potential of the F-FAS, according to the characteristics of the production mix and type of components to be assembled. By using the methodologies presented in the paper, one can first evaluate the convenience of the F-FAS approach with respect to traditional FAS technology and manual assembly, then identify the optimal design and settings of the F-FAS, according to the needs of a specific application. As a result, not only can the investment on the automated assembly system be accurately evaluated in advance, but also the return on investment can be maximized.