In modular educational systems, students are allowed to choose a part of their curriculum themselves. The rationale behind letting students choose their courses themselves is to enhance self-responsibility, improve student motivation, and allow for focus on specific areas of interest. A central instrument for bringing these systems to fruition is the timetable. However, scheduling the timetable in such systems can be an extremely challenging and time-consuming task. In this study, we present a framework for classifying modular educational systems in Europe that reflects different degrees of freedom regarding student choices and explore the consequences from the perspective of scheduling a timetable that satisfies all requirements from the organizational and pedagogical perspectives. For this purpose, we conducted interviews in Austria, Germany, Finland, Switzerland, the Netherlands, and Luxembourg, and applied the framework to these educational systems, finding that among them the Finnish system shows the highest degree of modularity. After analyzing the consequences of modularity from the scheduling perspective, we assess the necessity for automated scheduling methods, which are central to realizing the potential and many benefits of modular education. The framework developed in this paper can be used by educational systems to assess their degree of modularity and consider the right approach to timetabling based on it., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)