The complexity of timetable construction problems
This paper shows that timetable construction is NP-complete in a number of quite different ways that arise in practice, and discusses the prospects of overcoming these problems. A formal specification of the problem based on TTL, a timetable specification language, is given.
Specificially, we show that NP-completeness arises whenever students have a wide subject choice, or meetings vary in duration, or simple conditions are imposed on the choice of times for meetings, such as requirements for double times or an even spread through the week. In realistic cases, the assignment of meetings to just one teacher (after their times are fixed) is NP-complete. And although suitable times can be assigned to all the meetings involving one student group simultaneously, the corresponding problem for two student groups is NP-complete.
Keywordstimetable construction specification complexity
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