Implementation of a Maintenance Management System for CNC machines

Computer Numerical Control (CNC) machines are relevant manufacturing equipment, and their reliability directly influences the quality of processed products. The maintenance of this type of equipment plays a strategical role in the functioning of an organization and could account for a large part of the product life cycle cost. A well-implemented Maintenance Management System (MMS) allows understanding maintenance in a global way through the integration of knowledge and information derived by different actors (e.g., operators, maintenance team, CNC machine manufacturer) and sources (e.g., automatic alarms, maintenance team reports, manuals). In this paper, this approach has been applied to support the decisions about maintenance planning and interventions in the workshop of a research centre, which only produces prototypes for internal activities and not meant to be sold, with the aim to preserve as much as possible the performance of the CNC machines. After a first analysis of the current maintenance approach and the available data, the new maintenance strategy has been selected as a form of a preventive maintenance plan based on a fixed schedule, and it has been implemented in a dedicated MMS. The main framework of the system is based on: (i) classification of maintenance activities; (ii) assignment of these activities to different service units, according to required knowledge and safety; (iii) scheduling of preventive interventions; (iv) definition of checklist options and customizable answers to consolidate the execution of maintenance activities; and (v) training of maintenance team. The main results are the traceability of maintenance interventions to ensure the execution of maintenance tasks according to CNC machine manufacturers, and the involvement of machine operators in maintaining their equipment to improve the production performance and asset reliability. In fact, this approach ensures a methodology for those companies that consider the improvement of maintenance planning for the first time, allowing the final user to have a first basic maintenance coverage of the equipment together with the guarantee of starting to accumulate maintenance data. It is fundamental to overcome the gap between maintenance research and maintenance practice.