This article presents the general framework of development of a graphical tool for monitoring the performance indicators aimed to assess the effectiveness of a maintenance plan. This tool integrates the main indicators of maintenance management and provides information in a clear and simple way and facilitate the identification of guidelines for the proper allocation of technical and financial resources to fulfill given maintenance and production goals. The graphical tool focuses on the diagnosis, analysis, monitoring and control of the historical data regarding maintenance and operational events, and it has been designed for driving an effective reading and interpretation of it, to enriching the assessment of the performance of the current maintenance plans, supporting a well-informed decision making process concerning the management actions to be taken as part of the maintenance policies applied on physical assets.