Applying the Stock Removal Strategies

A stock removal strategy is a method of determining the bins from which to pick one or more quants of a product from stock. This process occurs after the system has determined a storage type based on the storage type search process. The search for a quant occurs within a storage type, or within a storage type group (the storage type group is commonly used in the strict FIFO removal strategy).

The stock removal rule defines which information the system shall use to sort the quants for the selection process. You determine the stock removal rule together with the storage types search sequence. A stock removal rule can also be assigned to a storage type directly, this would supersede a stock removal strategy which was found with the storage type search sequence.

For this removal strategy the quants are sorted according to the goods receipt date in the quant. There are actually two sort fields which can be used:

• WDATU:

  This is date and time of goods receipt.

• WDATU_DATE:

  This is only the goods receipt date, without time of day.

Use this rule when you want to apply the FIFO rule across several storage types. Apply the rule by using storage type groups. The stock is sorted by the defined sort fields within one storage type group. Each storage type search sequence can have a different storage type group.

Then defining a storage type search sequence, you can not only assign either a list of storage types or a storage type group. You could also have:

• An individual storage type and then a storage type group
• A storage type group followed by an individual storage type
• More then one storage type groups

Combined with a sorting rule by goods receipt date, this would not really be considered as stringent FIFO, but this gives a huge number of possibilities to implement your pick strategy.

For some warehouses the FIFO principle is not possible. For example, in the building materials industry, products that are to be removed from stock, such as lumber, are stacked on stock that is already stored in the warehouse. To execute the FIFO strategy, the warehouse worker would first have to remove the stock lying on top to get to the stock with the oldest goods receipt date. You can implement the LIFO strategy for such situations. When the system searches for a suitable quant to remove from stock, it always suggests the last quant that was placed into stock.

The three stock removal strategies FIFO, stringent FIFO, and LIFO, all use the same information, the goods receipt date. The trick is that for FIFO and stringent FIFO the sort sequence is the other way then for LIFO.

The same way you implement stringent FIFO, you could define stringent LIFO, by using a storage type group (if this would be required).

With this strategy, the system ensures that the products with the shortest shelf life expiration date are removed from stock first. This strategy is implemented like the other date-based removal strategies in a stock removal rule. The shelf life expiration date is specified as the sort criteria and applied to individual storage types or a storage type group.

With the partial quantities first strategy, the system takes a full handling unit or tries to remove stock in partial handling units first, depending on the required quantity, therefore optimizing the management of stock in the warehouse. With this strategy, the number of partial handling units in a storage type is kept to a minimum. This strategy is useful if you store material in a standard package quantity size (for example 100 pieces on one pallet) and you either have to pick:

• Full pallets:

  In this case you probably choose the pallet with the oldest goods receipt date.

• Less then full pallet:

  For this you pick from a partial pallet.

To implement this strategy, maintain the following settings:

• Define a stock removal rule with ascending quantity (piece) and a stock removal rule with descending quantity (standard HU). As additional sort field you would use the goods receipt date.

• Define quantity classifications for the warehouse in Customizing and use these to determine the stock removal rules.

• Define a packaging specification for the product or use alternative units of measure.

  The packaging specification or the alternative unit of measure is used to determine the Quantity Classification.

Let us stay for an example with the standard quantity of 100 pieces.

• For the first delivery you need 100 pieces. The system determines the quant with the oldest goods receipt date.
• For the next pick you need only 50 pieces. As you only have full pallets, the system uses the oldest quant and you take 50 pieces from that pallet.
• Next you need 100 pieces again. From the complete pallets again the one with the oldest goods receipt date is taken. Still one opened with 50 pieces exist.
• Then you need to pick 60 pieces. First the opened pallet (50 pieces) is used, then from the oldest full pallet 10 pieces are used. So the opened pallet has 90 pieces.

  From a strategy perspective this is done because there should never be more then one opened pallet. That means also that in the case of more then one opened pallet (which happens for example, in case of a blocked bin), for a partial pick the pallet with the lowest quantity is used first. From a technical perspective this happens because we simply sort the quants by the available quantity (as described above).

The system will never make something like an "optimized" pick, meaning in case of quants with various quantities, choose the one with the best fitting quantity. For this a Business Add-In (BAdI) implementation would be required.

You implement this strategy to remove stock based on quantity size. For example, if small quantities (cartons) are requested, the system searches the stock in storage type A. If large quantities (full pallets) are requested, the system searches the stock in storage type B.

The implementation of this strategy is very similar to Partial Quantities first. You require a packaging specification or alternative units of measure to determine quantity classifications. The difference is that with the help of the quantity classifications you determine different storage type search sequences rather then different stock removal rules.

With the fixed bin strategy, the system uses the storage bins that were assigned to the product master to find stock. But as there can be more then one fixed bin in a storage type, it is interesting to combine this strategy with another stock removal rule.

Consider the following scenario: Several fixed bins are assigned to the same product. You perform order based picking. If there is an open warehouse task for fixed bin 1, the system should create the next warehouse task for fixed bin 2 to avoid a situation where multiple workers are trying to pick from the same bin. To implement this, include the sort field PICK_ITM (Open Stock Removal Items per Storage Bin or PICK_QT (Open Quantity to Remove per Storage Bin) in your stock removal rule.

If you use fixed storage bin assignments and allow negative available quantities for a storage type, the system also considers the storage bins that do not contain any stock when determining the stock. This means that the system can create warehouse tasks (WTs) for which no stock exists. You use replenishment control to ensure that stock is available in the storage bin at the time of picking.

If you use this strategy, the system first proposes quants which do not have the preferred unit of measure (UoM). This strategy required the use of stock-specific units of measure (SUoMs).

The system compares the preferred UoM in the product's material master with the alternative UoM of the quants. If these UoMs are not the same, the system proposes the quant first. When you are working with SUoMs, the alternative UoM is set automatically in the quant during goods receipt posting.

For this stock removal rule you need to:

• Specify Preferred Unit Of Measure as the sort criterion (sort ascending).
• Specify at least one UoM as being stock-specific for your products.
• Maintain a preferred UoM in the product material master (in SAP S/4HANA) or in the warehouse product.