Due to the size and complicated geometry of modern belt conveyor installations and, consequently, the number of idlers installed, preventing failures is one of the biggest challenges. The research is based on the study of a unique belt conveyor of considerable length which is located in mountainous terrain. The study proposes an innovative algorithm that supports decision-making during inspections of conveyor idlers and an innovative use of existing measurement to estimate its remaining lifetime. The biggest challenge solved in the article is the further development of existing proposals with the possibility of adapting the theoretical models while also considering the variable measurement palette and the influence of the conveyor’s operating parameters. Additionally, by utilizing the adapted models, the article provides tools for determining optimal intervals between inspections. The article presents measurements and calculations of the tested conveyor as well as simulations confirming the validity of the proposed algorithm.