Maturity models can be used as tools which depict the developmental trajectories of entity classes in domains and evaluate the relative position of an entity within this framework. However, their development process has been the focus of researchers and practitioners ever since, resulting in different procedures, development approaches, and conceptual models. Thus, a major criticism of maturity models is the often missing conceptual and theoretical grounding when it comes to the interpretation of the concept of maturity. To address this shortcoming, our research approach focuses on the rigorous development of a multiple-pathway maturity model. By following a sequential, theoretically grounded process, the resulting maturity model can be viewed as an instantiation of the predefined conceptual components and characteristics in a predefined domain. We present and discuss the instantiated sector and size-specific maturity model for innovation capability in small industrial firms, which is developed by applying configurational methods on a dataset and thereby offers multiple pathways to maturity. This concept of equifinality is central to our approach. It has rarely been considered in maturity model development research, although it offers the potential to build more realistic models with greater applicability, especially in domains with many interdependencies.