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  Net Requirements Calculation for an Interchangeable Product

Use

The net requirements calculation identifies the net requirements for a product; in other words, the requirements that cannot be covered by stock or existing receipts. The net requirements calculation for an interchangeable product is performed, in principle, using the same rules as for the net requirements calculation for a product that is not interchangeable. However, it also takes the constraints into consideration, which result from the limited validity, the use-up strategy, and the relationship type between the product and its predecessor or successor.

Features

  • Relevant Requirements of a Product

    In the net requirements calculation, it makes no difference if a product requirement is an “original requirement”, or if the requirement has been forwarded to the product from the discontinued predecessor product by means of the product substitution order. However, the net requirements calculation is able to exclude requirements that lie after the discontinuation date and forward them to the successor product by means of the product substitution order. This depends on the relationship type between the product and the successor product and on the use-up strategy. It is the net requirements calculation for the successor that takes account of the forwarded requirements.

    The safety stock of a product represents a requirement in PP/DS that the system tries to cover during procurement planning. During the discontinuation phase, in order not to build up an unnecessarily large safety stock and to avoid the resulting unnecessary product substitutions, you should reduce the safety stock of a product being discontinued and do so in good time.

  • Available Stock of a Product

    As a rule, all pegging-relevant stock and all fixed pegging-relevant receipts for the product are regarded as available for the net requirements calculation. Due to the limited time validity of the product, the following constraints apply to an interchangeable product:

    • The net requirements calculation can use the stock of the product for product requirements whose requirements date/time is before the discontinuation date. It is only possible to use the stock for requirements after the discontinuation date if the use-up strategy permits this. If a product and its predecessor product are fully interchangeable, the net requirements calculation must first use the surplus stock of the predecessor product, depending on the use-up strategy.

    • The net requirements calculation takes account of fixed receipts of the product in the same way as stock: Requirements with a requirements date/time before the discontinuation date can use fixed receipts without restriction. Requirements lying after the discontinuation date can only use fixed receipts, depending on the use-up strategy and the relationship type. The product heuristic cannot automatically delete surplus fixed receipts. They appear in the product view, therefore, as surpluses with alerts. Delete these fixed receipts manually in interactive planning, if required.

    • Unfixed receipts are relevant in the net requirements calculation procedures Avoid Surpluses and Avoid Delays (see Avoiding Surpluses or Delays ). The same constraints apply to unfixed receipts as to fixed receipts. Product substitution orders from earlier planning runs are also regarded as unfixed receipts. The system processes them like other orders.

  • Safety Time

    The system only considers the safety time of a product in the validity period of the product. The system subtracts the safety time from requirements dates/times within the validity period of the product before the net requirements calculation (as usual). The system therefore shifts the requirements to a correspondingly earlier date/time and executes the net requirements calculation based on the shifted dates/times. The safety time is not used in the case of requirements with a requirements date/time after the validity period of the product.

    Note Note

    Procurement planning uses the safety time if you have entered a safety days’ supply on the Lot Size tab page in the location product master, and have selected a corresponding safety stock method.

    End of the note.