Updating the Sequence
When adding purchase order items (PO items) to a purchase order item group that was automatically created based on a purchase requisition or a production order, SAP Supply Network Collaboration (SAP SNC) adjusts the sequence of the group members. When doing so, the system considers that the customer might have changed the sequence manually after the creation of the group. In addition the user might have added external PO items and created relationships to these external PO items. Therefore, the system needs to consider the features of the group members (internal or external) and the existing relationships when adding a new PO item.
Note
For groups based on other ERP documents or manually created groups, you can only create a sequence manually. The system does not update the sequence of these groups automatically when a PO item is added afterwards.
To use this function, you must activate the business function Supply Network Collaboration 1 (SCM_SNC_GEN_1
).
Features
Basic Rules for Updating the Sequence
When determining the successor and the predecessor for a newly added PO item, the system considers the following rules:
The successor and predecessor must be compliant with the sequencing rules for the particular group type (purchase requisition or production order).
Each PO item can have only one successor.
Only an internal PO item can be the successor or predecessor of a newly added PO item.
Loops are not allowed (meaning that a PO item is not allowed to be directly or indirectly its own successor or predecessor).
An existing predecessor-successor relationship between a PO item and an external PO item is retained.
The system first determines the successor for the newly added PO item. Then the system identifies a predecessor.
Updating Sequence When Adding a PO Item to a Purchase-Requisition-Based Group
Determining the Successor
The supplier of the successor PO item must be the same as the goods recipient of the newly added PO item. If multiple internal PO items meet these requirements, the system randomly selects one of these items as successor.
Determining the Predecessor
The predecessor PO item must meet the following requirements:
The goods recipient of the PO item must be the same as the supplier of the newly added PO item.
The PO item must not already have an internal or external successor.
Reason: Only one successor is allowed for a group member.
The PO item must not be indirectly a successor of the newly added PO item
Reason: Loops are not allowed.
If multiple PO items meet the requirements, all these PO items are predecessor.
The following figures provide some examples on how the system determines the predecessor and successor for a PO item that you add to an existing group and are followed by an explanation:
Update Group Based on Purchase Requisition: Example 1
The grey bulk arrows represent the PO items of a group. The yellow bulk arrow represents the newly added PO item. S1 to S5 represent different business partners that can act as supplier or goods recipient in a PO item, as follows:
The business partner on the left hand side of a grey or yellow arrow is the supplier of the PO item.
The business partner on the right hand side is the goods recipient of the PO item.
A fine blue arrows represents a successor-predecessor relationship between two PO items.
In this example, there is a suitable successor for the newly added PO item.
In the following example, there is no suitable predecessor or successor for the newly added PO item.
Update Group Based on Purchase Requisition: Example 2
In the following example, there is a suitable successor for the newly added PO item.
Update Group Based on Purchase Requisition: Example 3
In the following example, there is suitable predecessor for the newly added PO item.
Update Group Based on Purchase Requisition: Example 4
Updating Sequence When Adding a PO Item to a Production-Order-Based Group
Determining the Successor
Among the internal PO items with operation numbers bigger than the new PO item’s operation number, the PO item with the smallest operation number is the new PO item’s successor. If there is no PO item with an operation number bigger than the new PO item’s operation number, the new PO item does not get assigned a successor.
Determining the Predecessor
Among the internal PO items with operation numbers smaller than the new PO item’s operation number, the system selects the one with the biggest operation number. However, this PO item is only a potential successor. To find out whether it is an allowed successor, the system analyses the relationships of the PO item. Depending on the result, the PO item is made the predecessor for the newly added PO item. The system considers the following cases:
The PO item under consideration already has an external successor.
In this case, the PO item cannot be the predecessor for the newly added PO item. Reason: A PO item is only allowed to have one successor. An external (manually created) successor has a higher priority than an automatically created internal successor. The following figure provides an example, followed by an explanation:
Update Group Based on Production Order: Example 1
The PO item 3 was added to a group that already includes PO item 2, PO item 4, and an external PO item EXT. Before PO item 3 was added to the group, the sequence was 2 → EXT → 4. In the first step, the system makes PO item 4, which is already successor for the external PO item, also the successor of the newly added PO item 3. Reason: PO item 4 is the PO item with the next higher operation number. PO item 2 is the PO item with the next smaller production order number and therefore a potential predecessor for the newly added PO item 3. However, PO item 2 already has the external successor EXT. Therefore, PO item 2 is not allowed to be the predecessor of the newly added PO item 3.
The PO item under consideration already has an internal successor.
The system considers the following cases:
If the PO item (example: PO item 2) has a successor (example: PO item 4) whose operation number is bigger than the operation number of the newly added PO item (example: PO item 3), the newly added PO item 3 is inserted between PO item 2 and PO item 4. The updated sequence is 2 → 3 → 4. The system removes the initial predecessor-successor relationship between PO item 2 and 4.
The following figure illustrates this example:
Update Group Based on Production Order: Example 2
If the PO item (example: PO item 2) has a successor whose operation number is smaller (example: PO item 1) than the operation number of the newly added PO item (example: PO item 3), the system leaves the existing relationship, which is 2 → 1, unchanged. The newly added PO 3 item does not get assigned a predecessor.
The following figure illustrates the example:
Update Group Based on Production Order: Example 3
The PO item under consideration has no successor.
The system checks whether the PO item under consideration is already a direct or indirect successor of the newly added PO item. Depending on the result, the PO item is allowed to be the successor for the newly added PO item, as follows:
If the PO item under consideration is already a direct or indirect successor of the newly added PO item, the PO item is not allowed to be a predecessor (otherwise a circle is created).
The following figure provides an example, followed by an explanation:
Update Group Based on Production Order: Example 4
PO item 3 was added to a group that already includes PO item 2 and PO item 4. Before PO item 3 was added to the group, the sequence was 4 → 2. In the first step, the system makes PO item 4 the successor of the newly added PO item 3 because PO item 4 is the PO item with the next higher operation number. After this step, the sequence is 3 → 4 → 2. PO item 2 is the PO item with the next smaller production order number and therefore a potential predecessor for the newly added PO item 3. However, a relationship 2 → 3 would create a circle. Therefore, PO item 2 is not allowed to be the predecessor for the newly added PO item 3.
If the PO item under consideration is not a direct or indirect successor of the newly added PO item, the PO item is the predecessor for the newly added item.
The following figure provides an example followed by an explanation:
Update Group Based on Production Order: Example 5
PO item 3 was added to a group that already includes PO item 1 and PO item 2. Before PO item 3 was added to the group, the sequence was 1 → 2. There is no successor for the newly added PO item 3 in the group, but a predecessor, which is PO item 2. Since PO item 2 is not a direct or indirect successor of PO item 3, it is allowed to be the predecessor of PO item 3. After the update, the sequence is 1 → 2 → 3.