The external system is assume responsibility for warehouse control and, if necessary, a specific part of warehouse management.

Scenarios 3, 4 and 5 must be considered in conjunction with an automatic warehouse. This section describes the third scenario. You should consider all three scenarios if, in a concrete situation, a decision regarding the use of the WM system in an automatic warehouse is to be made.

In a fully-automatic warehouse, both the warehouse as a whole and the specifications of the automatic warehouse systems must be taken into consideration in order to determine how the functions can be distributed effectively within this warehouse between the WM system and the external system. There is no standard solution for distributing the functions. This must be carried out separately for each individual customer and in accordance with the project in question. As in the other scenarios, warehouse management is always carried out by the WM system. This includes:

• Management of material stocks and storage bins

• Generation of all possible goods movements (stock placement/removal/transfer and posting changes)

• Determination of storage bins for movements with defined stock placement and removal strategies

The external system assumes full responsibility for warehouse control:

• Control of the conveyors

• Control of the material flow

• Optimization of resources

It is not always possible to accommodate all of the warehouse management functions in the WM system alone. There are meaningful ways of allocating the warehouse management functions to the two systems which may differ from one case to the next. The degree of automation implemented in the warehouse is of central importance here. In a simple automatic warehouse, all aspects of warehouse management will, in many cases, be controlled by the WM system. The external system only performs the warehouse control functions whereby the goods movements generated by the WM system can be optimized effectively by means of warehouse control. If the warehouse is more highly automated, the storage technique must also be taken into consideration when the transfer order is generated so that they can be used to optimum effect. For example, different pick points are selected via the movement type of the transfer order when the stock is removed. The following examples outline a method of distributing the functions between the WM system and external system in a warehouse that is automated to a relatively high degree.

A simple warehouse is, however, described in the first scenario. The interface between the WM system and external system is not used any differently in this case to the interface between a manual warehouse and a fork-lift control system.

Function distribution between the WM system and external system

WM:

• Initiates the goods movements

• Determines the destination for the delivered or prepared pallet

• Generates transfer orders from the GR zone to the pick point; the pallet number is printed on the pallet note in the form of a barcode

• Sends the generated transfer orders to the external system

External System:

• Scans in the barcode from the pallet note at the pick point in order to identify the pallet

• Determines the pallet type by checking the contours and allocates the storage bin

• Places the pallet into stock

• Reports that the pallet has been placed into stock to the WM system

WM:

• Generates transfer orders for the reported pallet movements

The delivered pallet (storage unit) is placed into stock in the SAP system or the pallet is first formed in the GR zone. The destination for the pallet that is to be placed into stock is then determined in the WM system using the application-specific data. When the destination is determined, either the storage type alone or the storage bin of a storage type is determined for stock placement. If stock placement is carried out, as described in this example, via the pick point, a transfer order from the GR zone to the pick point of an automatic warehouse will be generated. This transfer order is sent together with the necessary data to the external system with the standard IDoc WMTOID01. This IDoc is used, amongst other things, to transfer the pallet number.

The pallet to be placed into stock is transferred to the pick point where it is identified by the external system by means of the barcode. The storage bin is assigned by the external system to ensure that the conveyors are used as efficiently as possible. The pallet is placed into stock and a message to this effect is sent to the WM system. A pallet movement is reported via the standard IDoc WMSUID01. The pallet data with the storage bin must be structured in the same way as this IDoc on the external system side and sent to the SAP system so that a transfer order can be generated for the moved pallet in the SAP system and the movement generated by the external system posted again in the WM system.

Function distribution between the WM system and external system

WM:

• Initiates the goods movements

• Determines the type and scope of the stock removal

• Generates transfer orders from the warehouse to the GI or picking zone.

• Sends generated transfer orders to the external system

• (Sends reference number release to the external system

External system:

• Determines the most appropriate sequence for removing the individual pallets from stock

• Removes individual pallets from stock and moves them to a pick point determined by the external system

• Picks stock at the pick point with visualization of the individual pick items

• Confirms withdrawal and reports to the WM system

• Determines the storage bin for returning a pallet to stock that was not emptied as a result of withdrawal

• Returns the pallet to stock

• Reports the returned pallet to the WM system

WM:

• Reports confirmed transfer orders

• Generates transfer orders for the reported pallet movements

Stock removal or picking is initiated in the WM system. The scope and type of withdrawal depends on many different criteria; as an example, several delivery notes for a route are combined in one picking procedure. Transfer orders are generated for these delivery notes and are transferred to the external system with the standard IDoc WMTOID01.

1. Picking takes place on the basis of the delivery notes, i.e. each transfer order sent is treated as a separate picking request by the external system.
2. Picking does not take place on the basis of the delivery notes but is, as described in the example, referred to a route, i.e. the transfer orders that have been sent must not be picked straight away. Picking cannot start until all of the transfer orders for a route have been sent. Order picking is initiated in the WM system when the reference number is released. The reference number release is sent to the external system with the standard IDoc WMRRID01.

The picking request sent by the WM system which comprises one or more transfer orders is processed by the external system. The individual goods movements which result from the picking request are optimized by the external system, that is, the external system determines the sequence in which the individual pallets are removed from stock. If there are several pick points, the external system also assigns the individual picking procedures or pallets to the individual pick points. An optimum pick point assignment can only be made by the external system since the extent to which the warehouse systems resources are utilized plays an extremely important role in this situation as well. Picking takes place at the pick point. The goods and quantity to be picked are displayed by the external system on the screen of the pick point. Picking is confirmed and the differences recorded if any deviations occur. The picking procedure is reported to the WM system via the standard IDoc WMTCID01; the individual pallets (storage units) are reported. The data for this, with any differences that occurred, must be structured in the same way as this IDoc on the external system side and sent to the SAP system so that storage unit withdrawal and thus all of the transfer order items relevant to the storage unit can be confirmed in the SAP system.

All pallets that were not emptied as a result of withdrawal must be returned to stock. The pallets are transferred to the pick point. A new pallet type and corresponding storage bin are determined by checking the contours. The pallet is placed into stock and reported to the WM system with the standard IDoc WMSUID01 as in a normal stock placement procedure.

It is often the case in automatic warehouses that certain storage bins cannot be approached. Either it is not possible for the conveyors to negotiate certain conveyor routes or certain storage bins can no longer be reached by the warehouse systems. Since the storage bins are managed in the WM system, these storage bins must also be blocked as soon as possible in the WM system so that no further goods movements can be generated for these storage bins. The individual storage bins are blocked with the standard IDoc WMBBID01. The individual storage bins or entire aisles must be sent to the WM system by the external system in the same format as this IDoc. If the blocked storage bins are to be unblocked, the storage bins or aisles in question must be transferred to the WM system by the external system with IDocs which are structured in the same way.