This article presents research conducted in one of the largest mining companies in the EU—Jastrzębska Spółka Węglowa S.A. It relates to how the implementation of sustainable strategic management has affected methane projects. In the study, a literature analysis was first conducted, establishing the existence and significance of the research gap. Then, a group of experts from JSW S.A., during moderated workshops, prepared a multidimensional model describing the structure of the implementation of sustainable strategic management. The model was constructed and verified using the AHP method. As a result of the study, it was found that the implementation of sustainable strategic management resulted in a change of the company’s strategic priorities. Significant professionalization of management in the course of these projects was also observed. The most important and beneficial element of the implementation was the adoption of strategic goals related to the production of their very own energy based on methane emitted by mines. Other noteworthy elements of the change concern the introduction of continuous business case assurance during projects and the standardization of the project phase model.