HEEDS assumes that the academic hierarchy in the University is illustrated by the following figure:
A recurring decision made by the head of Academic of Affairs is the allocation of resources to the departments. The resource requirement of an academic department depends mostly on its teaching load, and this teaching load is determined by the number of classes for the subjects administered by the department.
The number of classes for a subject depends on the number of students who need the subject. Therefore, knowing in advance the number of students who will take a subject is crucial to the decisions made by chairs of departments and by the head of Academic Affairs.
The need for accurate forecast of future demand for subjects is the primary motivation for HEEDS. The secondary motivation is the reduction in time and effort expended by students during registration period. Typically, students compete with each other for seats in classes during registration. HEEDS pre-enlists students into classes, by creating an initial class schedule for each student. A student can accept the initial schedule "as-is" or modify it during the registration period. In either case, the student will spend less time and effort, compared to preparing a class schedule from scratch.