The goal of this paper is to discuss the island-based organization of a manufacturing-assembly system, based on the Seru-Seisan approach, whose main goals are to decentralize the production line and to improve personnel qualification. The aim is to show that a Seru-type production island/cell can be really profitable in case the operator could be supported by augmented-reality tools, such to help him in any complex processing operation. The efficiency/effectiveness of a Seru-type organization will be proved by verifying that it satisfies the main principles of “lean manufacturing”, stated in terms of mathematical formulation of both the lean goals and the lean processing model. A practical validation of the Seru-type approach will be done by analyzing an assembly unit, now under development and testing in CNH Industrial, where the operator is supported by an augmented-reality system designed in cooperation with Regola S.r.l.