The Overall Equipment Effectiveness (OEE) is a measure of a production system efficiency. OEE combines the Availability, Performance and Quality to an appreciated metric to qualify production systems. The Mikron assembly lines are constituted of multiple serial cells. Each of this cell is containing several units. OEE can be applied to both assembly lines and individual cells. This project focuses on the cells OEE improvements, which may not influence the line OEE proportionally. The goal of the master project is to provide tools and processes to identify combination of causes for cell performance loss. Correlation between loss of OEE and combination of events should be studied. Statistical indicators and graphical representations of the line results are key points to help lines tuning or client-side improvements.