A well-structured maintenance function is essential to remain competitive in the current industrial landscape, where maintenance has become a value-generating activity. The objective of this thesis investigates methodologies and techniques for the selection of maintenance strategies, alongside a comprehensive review of current condition-monitoring technologies, with the aim of proposing a structured approach for maintenance enhancement at the Mathi Alstrom paper mill. In the first part, a literature review is conducted to examine maintenance approaches, strategies, risk assessment tools, including Failure Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA), and the key concepts of the Industry 4.0 paradigm. The current maintenance practices ("AS IS" situation) at the plant are analyzed, highlighting the different strategies used depending on the type of equipment and the condition assessment techniques currently in place.