This diagram shows how a consignment traverses the various states, and the actions and conditions that affect those transitions.

The status is shown as a rounded rectangle, and the arrows indicate the action that causes the status change. Dotted lines, however, indicate operations happening in the background that cause the status to change. I've chosen to show cancellations in a lighter grey purely for clarity. Basically, a consignment starts in the unallocated state, and then goes through the various states until it is completed (when that carrier has finished providing status information for all the parcels in the consignment).

Certain transitions can happen automatically, without any user/developer interaction. For example, the "import and allocate" action can move consignments directly into the allocated state (or leave them in the unallocated state if an allocation was not possible).

Also, certain carriers do not require a manifest, resulting in a dummy manifest being created at a certain time (the cut-off time). This kind of manifest is actually delivered into MetaPack's internal systems, and not to the carrier.

Finally, the pick-up transaction type does not require a label. In this case, the act of allocating a carrier will move the consignment into the ready-to-manifest state.