Performance Evaluation of Selective and Adaptive Assembly Systems

Selective assembly systems are found in several manufacturing contexts, above all automotive and mechanical components manufacturing, where the tolerances imposed on the assembled product is much tighter than the tolerance imposed on the sub-components. Selective assembly consists in measuring the key quality characteristics of each sub-component after the machining/forming process and sorting the components into quality classes according to the measurement outcome. In order to improve the product quality, the assembly station is allowed to assemble only components from matching quality classes. By employing selective assembly, high precision assemblies can be produced from low precision components, at the cost of increasing the complexity of the system management and of decreasing the total production rate of the system. Therefore, an integrated quality and production logistics analysis of this system is needed, to correctly and profitably manage such trade-off. In this paper, a decomposition method is developed that allows predicting the integrated quality and production logistics performance of these complex systems.