Direct, operation-based picking using pick parts and crate parts has the following disadvantages in a repetitive manufacturing environment:

• If a run schedule quantity for which material has already been staged is changed, the information about the quantity requested may be lost (for example, after a new MRP run or after any changes in the planning table) and this material may be unintentionally staged again.

• Material is always staged with reference to the dependent requirements of the planned order as saved in the database. Here, changes to the bill of materials (BOM) are not taken into account. Since the BOM is usually re-exploded in the backflush, discrepancies occur between the staged material and the quantity to be backflushed.

• Due to possible discrepancies between the planned order BOM and the current BOM, WM material staging is only possible in the pull list if dependent requirements are read from the database and are not determined by the BOM explosion.

• Staging based on quantity is not possible (for example, the provision of partial quantities cannot be carried out).

Due to the disadvantages of staging materials using pick parts, it is necessary to also support material staging using release order parts.

• Material staging is flexible and takes place based on changes in production planning and in the BOM.

For release order parts, material staging takes place within a WM warehouse from the pull list at the inventory management level (with storage locations).

In the initial view of the pull list, the system examines the individual components from the Inventory Management view, that is, at the storage location level. When calculating the missing parts quantity for the individual components, the total requirements of the selected dependent requirements are checked against storage location stock.

From the WM view, it is not precise enough to examine a production area at warehouse level since the warehouse usually also contains several other production areas, storage areas for reserved stock / central replenishment locations.

A detailed view of the stocks in individual supply areas is not necessary for the pick items since the request is always made for the complete production quantity - independent of stock already at the production line.

The situation for the release order parts, that is for quantity-dependent staging, is quite different. Here, quantities to be provided are planned depending on the quantity actually available at the supply area. This stock is compared with the requirement quantities.

Another view was integrated into the pull list to allow a detailed display of the stock and requirement situation within the WM warehouse and thus make it possible to selectively carry out WM staging for release order parts.

The following information is included in this display:

• Total requirements

• Stock at the production storage bin level

• Required quantity for which provision has already been organized (transfer requirement)

• Available quantity in reserved storage

• The resulting quantity still to be staged

Depending on these values, you can then initiate WM material staging.

The choice of the selection type influences which types of WM material staging are supported in the pull list. However, the pick parts can be staged via RS headers/planned orders but not with the current BOM explosion. The release order parts, on the other hand, can also be staged if the current BOM is used for calculating the dependent requirements.

WM material staging via production orders is not possible from the pull list.

Note the following in the subsequent selection screen for selection according to RS headers/planned orders:

In the pull list, the system simply compares current stocks with the requirements determined via the selection to calculate the missing parts quantity. No dynamic availability check is carried out. This is valid at storage location level in the main view as well as at supply area level (storage bin stock) in the release order part view.

Therefore, for a correct display of the missing parts situation of a component at the storage location or supply area, you must process all requirements that exist here simultaneously.

• A second request for the same production line is triggered by a selection with the production period from 11–20 November. Here, the system calculates a total requirements of 50 pieces. As a transfer requirement for 100 pieces has already been created for this material, the system creates no new request. Therefore, this selection for material staging leads to incorrect results.