Predictive maintenance actions are beneficial to improve the reliability of the Utility's technical assets. Assessing the condition of the cable system while it is energized will enable the asset manager to better prioritize its decisions regarding cable rehabilitation or replacement programs. Partial Discharge On-line monitoring systems look rather promising, filling the gap that Off-line systems couldn't fulfil, as they give you a time continuous analysis of the cable system, enabling you to act before breakdown occurs. (4 pages)