Purpose: This thesis aims to support the transition from dedicated to a changeable machining system ensuring long-term adaptability. To fulfill this purpose three research questions are developed.  Methodology: Literature studies are conducted to create the theoretical framework for this thesis and answer the research questions. The literature search is structured to focus on selected subjects of machining systems, changeability, fixtures & tools, reconfigurability, and flexibility. A single case study in the tier-1 automotive was conducted to gather empirical data through interviews which are backed up by document studies, and observations along with a theoretical framework. The data gathered is analyzed through a thematic analysis.  Results: The empirical results are presented on a thematic pyramid model consisting of three levels: machining level, production level, and organizational level. The findings are related to the case study.  Analysis: The three research questions are analyzed using a thematic process digging deeper into each pyramid level by comparing the answers from the interviews, document studies, and observations to the theoretical framework. For research question three a conceptual support map is developed using a holistic perspective providing support for the tier 1 automotive industry when transitioning.  Discussion& Conclusion: The industrial contribution of this thesis shows the gap in the changeable thinking approach for tier-1 automotive manufacturers. The presented transition from DMS to CMS is supported through a conceptual map based on the case study findings. The academic contribution includes emphasizing the importance of changeability for long-term planning through the theoretical findings of flexibility and reconfigurability.  Delimitations: This thesis is limited to the challenges found in the case study done in the tier-1 automotive manufacturer. However, a holistic perspective is provided with the conceptual map to provide a starting point for transitioning to CMS, making the map adaptable to other industrial or academic needs.