Methods, systems, and apparatus, including medium-encoded computer program products, for synchronizing the manufacture of objects using two or more separate tools include, in at least one aspect, determining tasks to be performed in a shared build volume to manufacture a 3D object, assigning the tasks to respective queues, ordering the tasks within each queue of assigned tasks based on a spatial dimension extent, generating wait times within the queues in accordance with timing dependencies, identifying which of the queues of assigned tasks takes a most amount of time in accordance with temporal dimension extents and the wait times, creating at least one variant of the queues of assigned tasks, repeating the ordering, the adding, and the identifying to reduce a total time of manufacturing, and providing a finalized version of the queues of assigned tasks for conducting synchronized activities of manufacturing in the shared build volume.