Using Overall Equipment Effectiveness as a Driver for Improving the Productivity of Continuous Mining Systems

The gradual depletion of mineral deposits with favorable stripping ratios and ore grades, combined with the increased demand for raw materials used in digital and energy technologies, makes unavoidable the transition to the exploitation of deeper deposits with a high degree of technical difficulty. The mines developed for the exploitation of these deposits must effectively utilize the installed equipment to keep their production costs as low as possible. Using digital technologies to record and process equipment operating parameters enables the determination of several key performance indicators that can be used in decision-making processes. In this framework, the objective of this article was to demonstrate how the proven concept of overall equipment effectiveness (OEE) can be the driver for improved production performance in surface mines equipped with continuous mining machines. For this purpose, the lignite surface mine of South Field, located in the region of Western Macedonia, Greece, was used as a case study to investigate numerous parameters that affect the availability, utilization, and performance of continuous mining equipment. According to the results obtained from the analysis of the mine operation records for the period 2015–2020, the low OEE values achieved were related to the reduced availability as a result of frequent failures caused by the excavation of the hard rock inclusions of the overburden, as well as the reduced utilization, as a result of the multi-layered structure of the lignite strata that is dealt with frequent changes of the digging faces and the lack of personnel due to the ongoing restructuring in the context of lignite phase-out. Nevertheless, it was proved that OEE could be successfully used for the improvement of mine productivity by supporting decisions such as planning the annual maintenance of bucket-wheel excavators, managing the operators and maintenance personnel, and deciding about the remaining life span of equipment because of the energy transition.