This open access book opens up the question on what is sustainable by exploring how to measure sustainability. In doing this, it gathers academic and industry work from different geographical locations which embed the existing political reality. In particular, the practical use of the LCM methodologies and similar approaches are explored directly in an industrial setting to illustrate how to support decision making towards more sustainable practices. Furthermore, sector specific tools are provided to address limitations in operationalizing LCM practices. The book is part of the proceedings of the 12th Life cycle Management conference (LCM), it will include 40-60% best papers which will be selected from the abstracts received and published in LCM conference proceeding (corresponding to 30-50 papers considering the 800 abstracts already submitted). The Life Cycle Management (LCM) conference series is a premier global forum dedicated to environmental, economic, and social sustainability. Held biennially, each conference is organized by leading research institutions and industry experts in the field. The primary focus of LCM conferences is to present practical solutions for integrating life cycle approaches into both strategic and operational decision-making across various sectors, including science, industry, non-governmental organizations (NGOs), and public institutions. One central goal of the LCM conference series is to bring together practitioners and the scientific community. Therefore at least 50% of the participants of LCM conferences should come from industry and small or medium sized companies and government.