Abstract: Sequencing optimization is historically related to the case assembly lines. It is possible to consider a particular single station system where the models sequencing optimization is a critical problem: the Fully Flexible Assembly System (F-FAS) (Rosati et al., Assembly Automation Vol.1-2, 2013), an answer in case of high flexibility/low volumes scenarios. The system relies on a fullyflexible feeder, responsible for the parts delivery for assembly. Since in the F-FAS the feeding process is stochastic in nature, the defined sequence of model to assembly is critical in the complete order execution time.