As part of a planning run for a supersession chain, the system executes procurement planning for each product in the supersession chain. To do so, the system uses the relevant product heuristic. The product heuristic must be suitable for planning interchangeable products. This means that it has to consider the validity period of the product and, if necessary, forward requirements and surplus stock or fixed receipts to the successor product.
The process described here applies to all products in the supersession chain, except for the last product. Since the last product in the supersession chain does not have a successor, it is not possible to forward requirements. For that reason, the system regards the last product in a supersession chain as valid indefinitely, and the product heuristic plans the product like a normal, non-interchangeable product.
1. The product heuristic determines the requirements for the product, which you have to exclude from the net requirements calculation and the regular procurement quantity calculation from the very start, and forward to the next successor product. In principle, only requirements with a requirements date/time at which the product is already discontinued are relevant here. The forwarding of requirements depends on whether surplus stock or fixed receipts for the discontinued product can be consumed by product requirements or requirements for the successor product. The relationship type and the use-up strategy are therefore decisive. For more information, see Exclusion of Requirements and Stock Forwarding.
To forward a net requirement to the successor product, the product heuristic creates a product substitution order that consists of a receipt for the product and a requirement for the successor product.
2. The product heuristic executes a net requirements calculation for the product and offsets the product requirements with the available stock. It does not make any difference here if a requirement is an “original requirement” for the product or if it is a requirement that the system has forwarded from the predecessor product to the product by means of a product substitution order.
If the product and the predecessor product are fully interchangeable, the system first has to use up surplus stock and fixed receipts of the predecessor product (as far as the use-up strategy of the predecessor product permits this). To make the available surplus stock of the predecessor product available for a net requirement of the product, the product heuristic creates a product substitution order. This consists of a receipt for the product and a requirement for the predecessor product. The quantity of the product substitution order equals the quantity of the predecessor product that the product heuristic uses for a requirement.
The results of the net requirements calculation can be as follows:
¡ If there are no net requirements and no surplus stock and fixed receipts, procurement planning for the product is completed.
¡ If the net requirements calculation determines surplus stock and fixed receipts, and these can be consumed by the successor product, the system ensures that this stock and these fixed receipts are visible during procurement planning for the successor product.
¡ If the net requirements calculation determines uncovered requirements, the product heuristic has to perform a procurement quantity calculation for these net requirements and create procurement proposals (next step).
3. The product heuristic performs a procurement quantity calculation for the net requirements of the product and creates procurement proposals. These might be product substitution orders or regular procurement proposals, as follows:
¡ The product heuristic creates a product substitution order
§ If the product is not relevant for procurement, meaning that it is already discontinued at the planning time
§ If the product is relevant for procurement, but the requirements date/time lies after the validity period of the product
In these cases, the successor product has to be procured for a net requirement. This takes place with a product substitution order that consists of a receipt for the product and a requirement for the successor product. The quantity in the product substitution order is the same as the net requirements quantity.
¡ The product heuristic creates a regular procurement proposal if the product is relevant for procurement and the requirements date/time is within the validity period of the product. The procurement quantity calculates the product heuristic using the regular lot-sizing procedure. If you have set the remaining lot-for-lot order quantity in the location product master for the product, the product heuristic creates the last procurement proposal in the validity period of a product with a reduced procurement quantity. The aim is that the available quantity is 0 at the end of the validity period.
¡ If the requirements date/time is before the validity period of the product, the product heuristic also creates regular procurement proposals. The product heuristic puts the availability date/time of these procurement proposals to the start of the validity period of the product at the earliest.
4. The product heuristic resets the planning file entry for the product.
Procurement planning for the product is completed and the system executes procurement planning for the next product in the supersession chain using its product heuristic.