Manufacturing companies today face a volatile environment with a variety of challenges. Particularly, external factors such as the climate change, the digitalization, the material scarcity, or the shortage of skilled workers can be noted. At the same time, these factors are forcing companies to take measures to remain competitive and ensure their production system's future viability. In this context, established paradigms such as Lean Production and Industry 4.0 promise optimization potentials in terms of efficiency, quality, and costs. A new paradigm has gained importance with the emergence of the topic of sustainability, which aims to improve companies' use of resources and the recyclability of their products. However, there is no transparent model that enables companies to assess the status quo of their production system regarding these three paradigms, considering the interdependencies between the paradigms, and at the same time showing the implementation potential of methods or technologies within these paradigms. To support companies in rationalizing, digitalizing, and making their production processes more sustainable, this scientific paper presents a three-stage concept for a holistic maturity model. By providing transparency about the status quo of production systems in terms of Lean Production, digitalization, and sustainability, the model contributes to ensuring the future viability of such production systems in this highly competitive environment and under the political, social, and regulatory challenges.