When adding task participants or volunteers to a task, the Facility Management module will check to see if that person is already scheduled within one hour of that time to help avoid double-booking. You will be asked if it is OK to schedule this person so closely.
It also checks when you try to book tasks into the same venue at the same time that are not part of the same project. If the possible conflicts are part of the same project there is no warning because it would be expected that multiple tasks could be occurring in the same venue.