## 1 Introduction  
For all organizations and companies, a major disadvantage in terms of productivity and production results is encountering various production equipment failures, which automatically lead to lost production time and, implicitly, to increased expenses at the organization level. In this sense, the development of a maintenance strategy for production equipment is of primary interest. More and more companies worldwide are implementing preventive maintenance systems, which is a proactive maintenance strategy that involves the regular and routine maintenance planning of production equipment. By regularly scheduling the cleaning, repairs, adjustments, and replacement of component parts, a preventive approach increases the reliability over time and the productivity of work equipment. For companies that have not implemented a preventive maintenance procedure, the costs of operating production equipment can exceed up to 10 times the costs of a company that has such a well-established preventive maintenance procedure. The advantages of preventive maintenance include a significant increase in the level of safety of work equipment and, thus, a drastic reduction in the risks of accidents, the reduction of losses in the production process, fewer unexpected breakdowns of essential equipment for production, and reduced costs regarding possible emergency repairs. However, preventive maintenance also involves a number of disadvantages, including the possibility of excessive preventive maintenance, high implementation costs, and the need for more resources in terms of time and personnel. Even in this case, weighing the advantages and disadvantages of implementing a preventive maintenance system, it can be concluded that, in terms of development and a long-term, safe operation, it can bring very important benefits. A vitally important benefit that preventive maintenance can bring to an organisation is that it helps to anticipate faults and intervene to remedy them before they reach the critical point when the handling and operation of the equipment could represent a potential danger to the operator. A particularly important problem in quality assessment is keeping the quality up for as long as possible. The complexity of production systems and the optimization of maintenance systems have become a topic that has begun to attract the attention of many researchers [1; 2; 3; 4; 5; 6; 7; 8]. In mining operations, the role of maintenance is to optimise the speed, performance, and quality of the technological operations that are carried out in order to extract useful mineral substances. The well-performed maintenance of any mining equipment leads to the achievement of a minimum cost of their life cycle, to the reduction of the long-term costs of the mining companies, but, above all, to the reduction of the dangers that could arise due to the failure of the equipment, especially in the case of coal mines [8]. As shown by [PERSON] [9], the current requirements of the economy require the creation of products used in engineering that are very reliable and easy to maintain. In the studies conducted by [PERSON] et al. [8], a series of information is presented on how to make decisions regarding industrial maintenance, the proposed models, and the application of methods and tools. In the field of engineering, as with any production system, the most important elements are the production, maintenance, and quality of the operations and the products obtained. Any production equipment must be designed to work for a long period of time [10; 11; 12; 13; 14; 15]. However, their performance is affected by progressive degradation or wear until failure occurs. The mining industry was and remains one of the most challenging work sectors. The mining sector is the main source of national wealth for many countries. The mining field is a competitive one, and the equipment used in this field of activity is subject to difficult conditions and works in dangerous environments. Mining operations depend on the efficient use of mining equipment.