With the assignment of plant/storage locations in Inventory Management (IM) to the warehouse number in the Warehouse Management System (WM), the total stock balance between IM and WM remains the same when you post goods receipts and goods issues that result in stock quantity changes in the system. For these goods movements, two postings are normally required to complete the process – one in IM and one in WM. It is possible, however, to almost completely automate this process.
Several activities and key documents are included in the movement of goods in the warehouse. The most important of these activities and system documents are listed below. They are described in detail in other sections of this guide. They include:
Goods receiptsare inbound movements of stock that has been received as the result of a purchase order, production order and for other reasons. All goods receipts result in an increase in the total stock in IM and WM. The IM posting increases the total stock in IM and WM at the same time. In this case, WM has a "distribution" function to move the stock that was posted in IM from the goods receipt area to storage bins in the warehouse. For this purpose, a transfer order is created to determine the most appropriate storage bins. After the stock has been moved, the transfer order is confirmed.
For goods issues, the IM posting decreases the total stock in IM and WM. For example, the picking of goods for delivery to a customer is a goods issue in WM. In this case, WM has the function of finding the needed stock quantities in the individual storage bins in the warehouse and moving them to the goods issue area.
See also:Goods Receipt
The physical movement of materials from one plant or storage location to another, from one warehouse to another or from one storage bin to another in the warehouse is called a stock transfer in WM.
Stock transfers within the warehouse (within the warehouse number) do not result in a change in the total stock and require only a posting in the WM system (for example, when moving stock from one storage bin to another). This process is not relevant to IM because the total stock in the system remains the same.
There is a difference, however, for stock transfers that involve the movement of goods from one warehouse to another, one storage location to another or from one plant to another. In IM you can post this kind of stock transfer either in one or two steps. However, you only need to make an additional posting in WM if the storage locations concerned are managed in WM.
Consider a stock transfer from Plant 0001 Storage location 0001 (without WM) to Plant 0001 Storage location 0088 (with WM). In this case, WM must find storage bins for the stock that is transferred into the WM-managed storage location. For the removal of stock from storage location 0001, there is no WM activity. In this case, the total stock quantity in Plant 0001 does not change. The same applies to stock transfers from one plant to another: A second posting is required for WM managed storage locations.
See also:WM Interface to Quality Management
A posting change generally refers to a change in information about a particular material, for example when releasing stock from inspection. For most posting changes, the goods themselves remain in the same location and no physical stock transfer takes place.
See also:Stock Transfers and Replenishment
Transfer requirements are used to plan and initiate stock movements. They represent an existing requirement that goods in the warehouse need to be moved.
Automatic creation of transfer requirements
Depending on the type of movement, transfer requirements are normally created automatically as a result of a transaction in another SAP component. The IM posting (for goods receipts, goods issues and stock transfers) generates most transfer requirements automatically. For material staging to production through the production planning (PP) interface, you can create transfer requirements by simply releasing the production order. You can also create transfer requirements manually using a transaction that was developed for that purpose.
When a goods receipt for a purchase order is posted in IM, the system automatically generates a transfer requirement for the putaway. In this case, the goods are to be moved from the goods receipt area into the warehouse.
For a goods issue to a cost center, the transfer requirement contains an indicator for stock removal. In this case, the goods are to be moved from the warehouse into the goods issue area.
For the interface to Shipping (goods issue for a delivery), goods movements are not initiated by the transfer requirement, but rather by the delivery itself.
See also:Transfer Requirements
The transfer order is the "trigger" for the actual physical putaway, pick or stock transfer in the warehouse. Transfer orders used in WM are "move orders" that contain all the information needed to carry out the physical movement of goods in the warehouse. WM can create transfer orders automatically for both transfer requirements and deliveries so that no intervention by warehouse managers is necessary.
Once the transfer order has been created, you can print it. The TO includes both the source and the destination bin of the movement, so that the physical stock transfer can take place. When an IM goods receipt posting takes place, the transfer requirement that is created as a result of that posting serves as a reference document for the creation of a transfer order. In this case, the goods receipt area is already known as the source storage bin and the system uses a putaway strategy (seePosting Changes) to search for a suitable storage bin in the warehouse. The system can also create a transfer order using a delivery as the reference document (see Goods Issues Based on a Delivery) or using a transfer requirement that was generated to supply materials to production (see Goods Issue for Production Supply).
You can also create transfer orders manually, for example, to move stock from one storage bin to another within the warehouse.
WM manages negative stock in interim storage areas. When movement transactions that require the use of interim storage areas take place, the stock balance between IM and WM must remain constant. The use of negative stock postings makes this possible.
For example, negative stock postings occur for a goods issue based on a transfer requirement (a negative quant is posted to the goods issue area) or when a goods receipt is posted in WM prior to the goods receipt posting in IM. For an explanation of these processes, see Interim Storage Areas underWM Interface to Inventory Management (IM), Goods Issue Based on an IM Posting, Posting First in WM and Negative Stock Check.
As in IM, there are also WM movement types that influence the control of material flow. In WM the transfer order controls the movement and, therefore, contains information about the movement type. In WM, most movement types are determined automatically, either through the movement in IM (for example, goods receipt for a purchase order), or by a special transaction (such as, material staging in production). Usually, the movement types are automatically copied from the transfer requirement to the transfer order. It is only necessary to know and enter the movement type to manually create transfer orders for internal stock transfers.