Purpose of the paper:In family business research, sustainability has never received as much attention as large corporations despite the relevance of their global economic impact. Thus, the paper's aim is to investigate this issue by taking two key structures into consideration: longevity and trans-generational value.Methodology: Drawing on systems theory, we developed an exploratory conceptual framework (Trans-generational Sustainability Model -TSM) for family firms. We argue that the three pillars for the creation of trans-generational value, representing a longstanding value for family businesses, are growth, family success and local embeddedness quality. An exploratory case study on a long-lived Italian family firm (Amarelli) belonging to the Henokiens association, has been conducted to investigate some of the hypotheses that have been developed in relation to this preliminary model.Findings: In the case of Amarelli sustainability seems to be the result of the combination of a unique strategic orientation and distinctive competences. The presence of family members in management positions is a major concern for the "enlarged" family and high quality of local embeddedness which are likely to support the creation of trans-generational value.Practical implications: The balance between the three components of family firms' sustainability may provide directions for entrepreneurs in their family firms management, particularly during the succession phase or other disruptive changes involving their businesses.Originality of paper: This article provides a review of significant trends in the strategic management approach by studying family firms' sustainability. Its original contribution is twofold: firstly by its accumulating evidence that the creation of "enlarged" trans-generational value may determine family businesses' longevity and sustainability, and secondly, system theory seems as the leading theoretical perspective.