Automatic classroom assignment

Automatic classroom assignment assigns a classroom to a set of selected lessons in one go. You choose a set of candidate classrooms, the algorithm proposes an optimal assignment, and you validate after review — row by row if needed.

It is a tool for classroom allocation only. It does not move lessons in time, does not change their duration, does not assign resources and does not rerun the full timetable generation. To have classrooms placed during generation, see Automatic generation instead.

Where to find it

This tool lives in the listing view of the Distribute the hours and create the lessons screen (the table view, one row per lesson).

1. Display the lessons in the listing view.
2. Tick at least two lessons (selection column). If needed, use sorting and column filters to isolate the lessons to process — for example those awaiting a classroom.
3. Open the grouped classroom action in the header, Assign a classroom.
4. In the classroom selector, enable Automatic classroom assignment mode.

Remote or self-study lessons (according to their modality) are ignored: they need no physical classroom. Hybrid lessons remain taken into account. Leave lessons whose classroom is locked out of the selection: the tool does not override a lock.

Choosing the set of candidate classrooms

In automatic mode, the selector displays classrooms grouped by site then by building, with checkboxes at three levels:

• ticking a site takes all its eligible classrooms;
• ticking a building takes all the classrooms of that building;
• ticking a classroom adds it individually.

Classrooms already assigned to the selected lessons are pre-ticked. A classroom whose specialisation matches none of the selected lessons, or that is too small for all the compatible lessons, is disabled. The capacity turns red when the classroom cannot host any of the compatible lessons, orange when it can host only some of them.

Confirm the set to start the computation.

What the algorithm does

From the chosen set, the algorithm assigns one classroom per lesson, respecting strict rules and optimizing the rest:

• the specialisation required by the lesson's subject;
• the classroom's capacity against the lesson's headcount;
• the classroom's existing occupancy on the time slot — lessons from other timetables or other linked accounts, events, classroom time constraints, shared large rooms;
• a preference for the lesson's reference site;
• alternate weeks: two lessons that never fall in the same week can reuse the same classroom.

The algorithm can reshuffle classrooms among the selected lessons to house them better, and prefers the smallest suitable classroom. When the current classroom already suits and another would bring only a marginal gain, it keeps it rather than producing a needless change. If no classroom in the set suits, the lesson is left without a solution.

Review, adjust, apply

The computation opens a preview window: as long as it is open, the actual timetable is not modified. Each row carries a status — assigned, unchanged, no solution, or manually adjusted — along with the previous classroom and the proposed one.

• Adjusting a row: click its proposed classroom to open the regular selector. The manual choice is not limited to the initial candidate set; the row switches to the "adjusted" status and any conflicts are immediately recomputed on all rows.
• Resetting: a button restores the algorithm's proposal on the adjusted rows.
• Unticking a row excludes it from being applied.
• Validate applies the ticked rows to the timetable; Cancel closes without changing anything.

After applying, the modified lessons flash and a summary shows the number of lessons modified, unchanged and without a solution.

Notes

• A lesson that carried several classrooms can be brought down to a single one by the automatic assignment.
• A lesson with no positioned time slot can still receive a classroom (by set, specialisation, capacity and site), but no time conflict can then be checked for it.
• To simply set the default classrooms (the class's or the teacher's, excluding special classrooms) or clear assignments, the Actions menu offers dedicated mass actions — see Distribute the hours and create the lessons.