  In a perfect world, each high school student could pursue their interests
through a personalized timetable that supports their strengths, weaknesses, and
curiosities. While recent research has shown that school systems are evolving
to support those developments by strengthening modularity in their curricula,
there is often a hurdle that prevents the complete success of such a system:
the scheduling process is too complex. While there are many tools that assist
with scheduling timetables in an effective way, they usually arrange students
into groups and classes with similar interests instead of handling each student
individually. In this paper, we propose an extension of the popular XHSTT
framework that adds two new constraints to model the individual student choices
as well as the requirements for group formation that arise from them. Those two
constraints were identified through extensive interviews with school
administrators and other school timetabling experts from six European
countries. We propose a corresponding ILP formulation and show first
optimization results for real-world instances from schools in Germany.
