Background: Care pathways are useful for optimizing patient or disease management. However, in practice, the implementation of this concept remains below its potential. Probably because it is a complex intervention in complex systems. In such cases, modeling is beneficial. Thus, facilitating the representation of care pathways can go through the formalization of a standardizable part. Indeed, certain structural elements of care pathways are systematically present, whatever the area of healthcare. The objective of the present study will be to identify and develop a list of these key factors, called “invariant determinants of care pathways”. Methods: This qualitative study will adopt a descriptive design. Semi-structured interviews will be conducted with different types of health experts: practitioners, academics, and institutional representatives. An interview guide was designed in 3 research sections: identifying the main key elements of the care pathway concept, defining the main determinants considered as pathway invariants, projecting the interviewee into a broader perspective of systemic pathway description. Once collected, data will be anonymized, transcribed and analyzed according to a thematic approach. The analysis report will follow the COREQ checklist. This research project has been validated by the ethics committee of Lyon (n°2022-05-19-003). Discussion: The results of our research will enable us to use a systems approach to gain a better understanding of the concept of care pathways and, in the longer term, to model these pathways. This study will make it possible to identify and characterize the invariant determinants of care pathways. However, although these factors are systematically present, their influence on the care pathway varies. Methods for calculating the power of impact will be used to assess this variability. Then, for a more exhaustive approach, specific factors known as variant determinants will be identified. Determining the invariant and variant determinants will enable each care pathway to be modelled.