Supply chain rules are set up in 'Supply Chain Policy. Open' (CRS709).
The general rule for a supply chain is that whenever it is changed (quantity, release of proposal or allocation of stock) the supply chain relationships (pre-allocations) and all proposals for the levels below it are deleted, and the supply chain is recreated.
The recreation reuses all the existing allocations and released orders that were connected to the original supply chain, but proposals are not reused. They are deleted and recreated.
An exception is when a proposal is APP planned. Depending upon parameter settings, the APP planned proposals can be reused, or when a proposal on the lowest level is connected to several supply chains.
An item is considered a supply chain item when a supply chain policy has been added to the item/warehouse record in (MMS002/E). The supply chain is either generated on-ine or in a batch, depending on the setting in (CRS709).
The supply chain generation is managed through an internal job queue which ensures that two events are not performed at the same time on a single supply chain.
The supply chain is always generated from a customer order line or from a released distribution order line. This is always the starting point for a supply chain.