1. A method performed by a synchronization system incorporated in a physical computing system programmed to synchronize a source bill of material stored on a first networked physical computing system with a target bill of material stored on a second, separate networked physical computing system, the method comprising; with the physical computing system, monitor said source bill of material at said first networked physical computing system for revisions; in response to a determination by said physical computing system that a revision has been applied to a source node from a tree structure representing said source bill of material at said first networked physical computing system after a corresponding target node from a tree structure representing said target bill of material at said second networked physical computing system was last updated, calculating a change from said source node to said target node with said physical computing system; determining whether said calculated change matches a difference provided by a revision history associated with said source bill of material at said first networked physical computing system; and synchronizing the two bills of material by updating, with said physical computing system, said target node at said second networked physical computing system with said revision only when said calculated change matches the difference provided by a revision history associated with said source bill of material at said first networked physical computing system, so that manufacturing that is based on said target bill of materials located at said second networked physical computing system is accurate with respect to said source bill of materials located at said first networked physical computing system.