**Nicola Comand \*, Riccardo Minto, Giovanni Boschetti, Maurizio Faccio and Giulio Rosati**

Department of Management and Engineering, University of Padova, Via Venezia 1, 35121 Padova, Italy **\*** Correspondence: nicola.comand@phd.unipd.it; Tel.: +39-049-827-6810

Received: 1 May 2019; Accepted: 5 August 2019; Published: 7 August 2019

**Abstract:** Assembly kitting lines typically deal with components that present different quantities in the final kit. Re-configurable feeders are not advisable for low quantity components since this solution leads to high inefficiency, due to the time required for retooling and for the feeding rate unbalance between the components. On the other hand a fully flexible feeder can increase the flexibility of the system at the cost of reducing the throughput. An assembly kitting problem was therefore addressed in different ways for low quantity components and high quantity components, studying the two different subsystems that compose a hybrid flexible assembly system. To optimize the re-configurable feeders, which supply the high quantity components, the opening sequence of a system composed by several hoppers was analyzed. We propose a solution which replaces the weighing device with a vision inspection system, showing its impact on the productivity of the line. A model coded into a Matlab script was developed to perform the optimization of the system and understand its behavior. Furthermore a fully flexible assembly system was developed in the laboratory in order to test the kitting of the low quantity components with the proposed subsystem. Finally the Overall Equipment Effectiveness of the line was calculated to evaluate the possible improvements obtained by the proposed solution.

**Keywords:** hopper; optimization; sequencing; kitting; H-FAS
