Can I relaunch an automatic placement for a period during the year?

Yes. If you need to recalculate a new timetable over a defined period (for example, the time of a school outing), make a copy of the database in use, make the necessary changes on this copy and then launch a new automatic placement.

Once all the placement steps have been completed, import the modified timetables into the database in service for the course period in question only, with the command Imports/Exports > EDT > Import the teachers'/classes' timetables.