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MWMTO003

User Exits for TO Processing
With this user exit, you can integrate your own stock placement strategy into TO processing.

General information about transfer order processing

Transfer order processing and confirmation in the WM system are divided into the following programs:

  1. SAPML03T Screens, transactions
  2. SAPLL03A Item creation (TO core)
  3. SAPLL03B Function modules for external purposes
  4. SAPLL03T Update tasks

These four programs work together as follows:

SAPML03T contains all the transfer order processing screens. All related transactions are initiated using screens from this program. All corresponding data is read, checked and recorded here (transportation requirements in transfer order: transportation requirements, transfer order: confirmation, etc.)

Actual creation or confirmation of items occurs via function modules in SAPLL03A , where the transfer orders are first created and recorded internally as the putaway and picking strategies and several checks are run. Changes in storage location, storage unit or stock that may arise from individual transfer order items are simulated in internal tables.
Item creation and confirmation occurs in two steps. First, the item is generated internally and all checks are carried out. Then, the internal tables are updated via a second function module and the transfer order items are added internally. You can view this two-step process by running transfer order creation in the foreground (screen SAPML03T 102). First, the system generates the transfer order item, then issues a warning. If entries are made on the screen, the system regenerates the transfer order item (including all checks) and the previous one is discarded. The internal tables are updated after the warning disappears.
The confirmation process follows a similar procedure.

User action 'post' in SAPML03T is carried out after an item is created or confirmed, which in turn calls up function module SAPLL03A , which then activates the update function modules in SAPLL03T. These function modules are normally processed asynchronously (supplement IN UPDATE TASK), but can also occur synchronously (see below). All changes in storage location, storage unit, stock, transportation requirements or transfer orders are made in these function modules.

SAPLL03B contains function modules for creating and confirming transfer orders which can be used instead of transactions. First, the normal screen run of the parameters transmitted is reviewed. Reading, checking and recording of the data and part of the flow logic occurs via external performs in SAPML03T and in a common data area, to avoid redundant code. Item creation and confirmation takes place in function modules found in SAPLL03A.
Function modules L_TO_CREATE_TR and L_TO_CREATE_DN, for example, are used in collective processing in the SAP standard system. Updating occurs synchronously in this case.

Transactions in SAPLL03A and SAPML03T

Some checks within the transfer order creation and confirmation processes depend on the transaction concerned. This transaction (field VORGA) is placed at the disposal of all user exits so that the system can react as required for the transaction involved.

Relevant values:

  1. "TB" Transfer order for transfer requirement
  2. "LF" Transfer order for delivery note
  3. "TL" Transfer complete storage unit

Homogeneous storage units can also be transferred explicitly. In this case, the value of the field is LTAP-HOMVE = 'X'.

  1. "IV" Clear inventory
  2. "U1" Create first item for posting change
  3. "U2" Create second item for posting change
  4. "QB" Confirm storage unit for stock removal from SU-managed block storage area

Within the SU-managed block storage ares, the item type (POSTY) of a TO item is of interest. It is set when the source data is determined and can have the following values:

  1. " " Normal transfer order item
  2. "1" Quant-neutral stock removal that requires verification of storage units during the confirmation process
  3. "2" Storage unit verified during confirmation

Items with item type "1" are deleted as soon as confirmation is complete.

Call transactions and relationships

The modification consists of four user exits in SAPLL03A. The respective function modules are EXIT_SAPLL03A_001 through EXIT_SAPLL03A_004. In addition to the activation in transaction SMOD, you have to select the stock placement strategy in the storage type control. The standard stock placement strategy is usually " ". If no updates are required at storage bin level, you can use this stock placement strategy in connection with the SAP stock placement strategies B or P.
The function modules have the following meaning:

  • Function module EXIT_SAPLL03A_001 is called in order to find an appropriate storage bin for a given storage type. As an option, it is also possible to find an additional appropriate storage unit providing I_LTAP-NLENR is still initial. If no storage unit is transferred, the normal storage unit specification is used. The found storage bin must be blocked (block object ELLAGPE) before it is returned. Storage bins that cannot be blocked are not used. Abend messages and system messages may be issued directly whereas warning messages and error messages must be issued via the interface (see below).
  • Function module EXIT_SAPLL03A_002 is called in order to check a storage bin that is generally given by the user. As an option, it is also possible to find an additional appropriate storage unit providing I_LTAP-NLENR is still initial. This function module is not called if function module EXIT_SAPLL03A_001 was performed directly before, that is, the latest determined locations are no longer checked. Because of the division in the TO creation described above, it is still possible that a storage bin is determined and proposed to the user. If some interaction is performed on the screen now, the items are created again. If you cancel the proposed storage bin, function module EXIT_SAPLL03A_001 is performed. If you confirm or overwrite the storage bin, this definite storage bin is checked with function module EXIT_SAPLL03A_002. Abend messages and system messages may be issued directly whereas warning messages and error messages must be issued via the interface (see below).
  • Function module EXIT_SAPLL03A_003 is called if the TO item in question is created internally, for example, to update your own internal tables. (Second part of the item creation). No error messages may be issued here.
  • Function module EXIT_SAPLL03A_004 is called if the TO item in question is deleted internally, for example, to update your own internal tables or cancel updates with function module EXIT_SAPLL03A_003. No error messages may be issued here.

Parameters and options of the individual function modules

EXIT_SAPLL03A_001: Finding a suitable storage bin

In order to be able to use the function module, you must create Include ZXLTOU03.
The following parameters are available:

Import parameters

  1. I_LTAK The respective TO header that contains, for example, the reference documents such as the transfer requirement number and so on.
  2. I_LTAP The TO item that has been created so far (check the source data)

Please refer to the interface documentation of function module L_TO_PREPARE_ITEM_INT for more information on the filled fields in I_LTAK and I_LTAP.

  1. I_MLVS Material master
  2. I_MGEF Hazardous material master
  3. I_T331 Control data of the storage type in which a storage bin is searched for
  4. I_T333 Movement type with which the TO is created
  5. I_T340D Warehouse number control
  6. I_VORGA Transaction within the TO processing (see above)

Export parameters

  1. E_NLPLA Found storage bin
  2. E_NPPOS Item in storage bin found. This parameter is optional and only relevant in connection with strategy P.
  3. E_NKDYN Indicator that the found storage bin is a dynamic storage bin, that is, it possibly does not exist in the database and should be created in the update program.
  4. E_NLENR Found storage unit. This parameter is optional. It is not used if I_LTAP-NLENR is filled. If no storage unit is found, the common storage unit specification is performed. (one SU per storage bin at the most => search for and use it, if available, several SUs per storage bin are permitted => create new ones)
  5. E_SUBRC Processing return code with the following values
    1. R_CUS_OK => Use transferred storage bin
    2. R_CUS_EXIT => Continue storage bin search in the next storage type
    3. R_CUS_STEIN_L => Search for empty storage bin in this storage type
    4. R_CUS_WARNING => Use transferred storage bin and send a warning message
    5. R_CUS_ERROR => Send an error message
  6. E_MSGID Message ID for the error message
  7. E_MSGNO Number of the error message
  8. E_MSGV1 First variable in the error message
  9. E_MSGV2 Second variable in the error message
  10. E_MSGV3 Third variable in the error message
  11. E_MSGV4 Fourth variable in the error message

Error messages and warnings within SAPLL03A require special treatment. On the one hand, the messages must be logged; on the other hand, warning messages can only be sent from SAPML03T after completion of the transfer order item. The following procedure is recommended for the customer exit: in the parameter E_SUBRC you determine whether an error message or a warning is to be sent (R_CUS_ERROR or R_CUS_WARNING). The message ID, error number and parameters can be set in the respective parameters. It is important that the message variables with WRITE ... TO E_MSGVx are passed on so that, if required, existing conversion exits can run. Message variables that are not used should not be initialized (CLEAR E_MSGVx).

Information on the status of transfer order processing

Using the function module L_TO_CREATE_GET_INFO you can obtain information on the current status of transfer order processing. In addition to Table TAP with the transfer order items already created, you can use the following tables: PSPERR, LSPERR, QSPERR and SSPERR. These tables contain the storage bins, storage units and quants affected by the transfer order. However, the contents of the more important fields do not match the status in the database. Instead, they appear as if the transfer order items created up to now have been posted. The update of the item currently being posted is not included in the table.

If, for example, a bin is read in the user exit, we recommend that you have the system first check in Table PSPERR and then, only if data access is unsuccessful, to read the database. If this is not possible (for example, the bin is read by the index for empty bins), a bin that has been read should still be compared with Table PSPERR.

The only exception to this rule is a quant affected by blocking logic B. In this case, QSPERR has the status that would exist on the basis of the current transfer order. Changes that arise from parallel transfer orders are only partially included. If, for example, transfer orders 1 and 2 (in this sequence) access the same quant and the respective items have already been created internally, QSPERR contains the stock of transfer order 1 minus the current item and for transfer order 2 the stock is minus both items. Therefore, to have the current stock in each case, the database stocks must be compared with the global blocking table (blocking object ELLQUAY via function module "ENQUEUE_READ" read and evaluate). Whether or not this exact stock reading is required should be decided in each individual case.

The following example of a stock removal via user exit may be of help in making this decision:

Bin stock database: 10 pieces
TO 1 removes 5 pcs and first creates the item internally
TO 2 wants to have 10 pcs removed from stock.

The user exit also decides on this bin. The quant is not in the internal table because no internal item yet exists. Irrespective of whether the user exit proposes the bin with a stock of 5 pcs or 10 pcs, transfer order 2 (providing there is a positive stock balance) would at most take 5 pieces and would try to supply the remaining 5 pieces by means of a further item. Within the user exit, the correct stock is not important for the stock removal to be "correct". It is only important if it affects a decision, that is, if the user exit proposes another bin because only 5 pieces could be removed from the first bin.

Table IBDBATCH is available for you to create your own stock removal strategy. This table is important for batch-neutral documents if you want your own stock removal strategy to be influenced by the standard batch search function.

All the above tables are predefined for the user exit. If the system is to access one of these tables within the user exit, the current version must be called up via the function module L_TO_CREATE_GET_INFO. The following example shows you how to call up Tables PSPERR, QSPERR and TAP. The other two tables are not of importance because there is no SU management involved:

CALL FUNCTION 'L_TO_CREATE_GET_INFO' EXPORTING I_LAGP_COPY = 'X' I_LQUA_COPY = 'X' I_LTAP_VB_COPY = 'X' TABLES T_PSPERR = PSPERR T_LSPERR = LSPERR T_QSPERR = QSPERR T_SSPERR = SSPERR T_TAP = TAP T_BDBATCH = IBDBATCH.

The table parameters must always be specified; only the marked tables (with "X") are copied.

Table IBDBATCH can only be called up by user exits from SAPLL03A. Otherwise the content is undefined.

EXIT_SAPLL03A_002: Checking a given storage bin

In order to be able to use the function module, you must create Include ZXLTOU04.
The description of the parameters basically corresponds to the descriptions of function module EXIT_SAPLL03A_001. Below, only the differences are described.

Import parameters

  1. I_LTAP The TO item that has been created so far (check the source data), the destination bin location is filled (I_LTAP-NLPLA)
  2. I_T331 Control data of the storage type of the storage bin that is checked

Export parameters

  1. E_NPPOS Position in the storage bin to be checked. This parameter is optional and only relevant in connection with strategy P. It is not used if I_LTAP-NPPOS is filled.
  2. E_NKDYN Indicator that the checked storage bin is a dynamic storage bin, that is, it possibly does not exist in the database and should be created in the update program.
  3. E_NLENR Found storage unit. This parameter is optional. It is not used if I_LTAP-NLENR is filled. If no storage unit is found, the common storage unit specification is performed. (one SU per storage bin at the most => search for and use it, if available, several SUs per storage bin are permitted => create new ones)
  4. E_SUBRC Processing return code with the following values
    1. R_CUS_OK => Use checked storage bin
    2. R_CUS_WARNING => Use checked storage bin and send a warning message
    3. R_CUS_ERROR => Do not use checked storage bin and send an error message
  5. E_MSGID Message ID for the error message
  6. E_MSGNO Number of the error message
  7. E_MSGV1 First variable in the error message
  8. E_MSGV2 Second variable in the error message
  9. E_MSGV3 Third variable in the error message
  10. E_MSGV4 Fourth variable in the error message

Parameter E_NLPLA is no longer applicable. No new destination bin location can be set.

EXIT_SAPLL03A_003: Updating your own internal tables when you create an item.

To fill the function module with data, create the include ZXLTOV05.
The following parameters are available:

Import parameters

  1. I_LTAK The respective TO header
  2. I_LTAP The complete TO item that is now included in the internal tables of SAPLL03A including all its characteristics
  3. I_VORGA Transaction within the TO processing

There are no export parameters.

If table TAP is read at this time, the item to be currently created is not yet contained.

EXIT_SAPLL03A_004: Updating your own internal tables when deleting an item

To fill the function module with data, you must create Include ZXLTOU06.
The following parameters are available:

Import parameters

  1. I_LTAK The respective TO header
  2. I_LTAP The complete TO item that is deleted from the internal tables including all its characteristics

  3. Function/Program:
    • EXIT_SAPLL03A_001: Internal Putaway Strategy: Find Storage Bin
    • EXIT_SAPLL03A_002: Internal Putaway Strategy: Check Specified Storage Bin
    • EXIT_SAPLL03A_003: Internal Putaway Strategy: Update New Items in Internal Tables
    • EXIT_SAPLL03A_004: Internal Putaway Strategy: Update Internal Tables of Deleted Items

02-Oct-2005