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Late exclusive material block (material enqueue) for goods movements

Description

As of Release 3.0D there is a shorter material block for goods movements. This new development is available as an alternative to the exclusive material block used so far in the system. It is intended for customers who cannot enter a large number of goods movements (goods issues for deliveries or withdrawal of goods for production orders) because certain materials occur in several deliveries or orders and are often blocked by other users.

Exclusive material block (procedure used so far)

In the first procedure, when the material master data is read for the first time for a goods movement, tables MARC (plant data) and MBEW (accounting data) are blocked exclusively up to the end of the goods movement posting. Another user cannot work with the material during this time. This ensures that the goods movement is valuated correctly and that the stock quantities and values are updated correctly. The disadvantage of this procedure is the long blocking time (from the time when the material master data is read for the first time during the entry of the goods movement up to the closing of the update posting).

Late exclusive material block

The new procedure provides for optimization of the material block for the following reasons:

The advantage of this procedure is that several users can enter goods movements at the same time.

The disadvantage of this procedure is that the material master record is read several times and, in the case of an outward stock movement, block entries of other users in the ATP server must be taken into consideration. These additional accesses have a negative effect on performance.

Procedure for exclusive material block at a later time

1. Time 1: the goods movement is entered into the system
When a goods movement is entered, the material master data is read for the first time. If the system determines that the material is managed in serial numbers, the system implements the exclusive block procedure used so far. The procedure for all other materials is as follows:
MBEW block:
A shared lock is set for table MBEW (material valuation data).
With the shared lock, several users can enter goods movements for the same material at the same time. It is not possible to enter a transaction that requires an exclusive block. This prevents another user from changing the material price or other material data at the same time.
The shared lock remains active until update processing is complete.
MARC block:
A shared lock is set for table MARC (plant data). Since the table is not blocked exclusively, all current outward stock movements must be taken into account to avoid unwanted negative stocks. For this purpose, a block entry EM07M for the respective stock (for example, withdrawal from unrestricted-use stock) is set on the central ATP server when you enter an outward stock movement. All the block entries of other users in the ATP server are read, and the current stock in the material master record is reduced by the outgoing stock reserved by the other users. If this results in a negative stock balance, the system issues an error, provided no negative stocks are allowed for this material.
As soon as a user changes the quantity entered, the system must read the material master record and the block entries of other users once again.
Block entries:
At time 1, for example, the following entries exist for withdrawal from unrestricted-use stock:
2. Time 2: the goods movement is posted
Since the MBEW data is not blocked exclusively when the material master data is read for the first time, the material valuation data must be read a second time when the goods movement is posted. First the MBEW data is blocked with the block entry EM078W in addition to the shared lock. The system checks whether the exclusive block is actually necessary and whether it can be replaced by a shared lock.
The exclusive block of the MBEW data remains until the update processing is complete if:
Goods movements can still be entered with the shared lock, but it is not possible to post the movement as long as the exclusive block is set.
If the exclusive block is not required, it is replaced by the shared lock EM07W with the same name.
All shared blocks are kept until the end of update processing.
Block entries:
At time 2 up until the end of update processing, the following block entries exist:

Example of late exclusive material block

Two users (USER1 und USER2) enter a goods withdrawal of material XX11 at the same time in client 003, plant 0001, storage location 0001.

Time 1: the goods movements are entered.

Only shared locks are set for both users. The following block entries are set:

User Shared Table Block argument
USER1 X EM07M 003XX11 00010001MARD0001 L01
USER1 X MARC
003XX11 0001
USER1 X MBEW 003XX11 0001
USER2 X EM07M 003XX11 00010001MARD0001 L01
USER2 X MARC 003XX11 0001
USER2 X MBEW 003XX11 0001

These entries have the effect that

  • a third user can enter a further goods movement for this material at the same time. The quantities already entered by USER1 and USER2 (block entries EM07M) are taken into consideration for the statistical availability check.
  • a third user cannot change the material price or other material data.

Time 2: a goods movement is posted

USER1 now posts the goods movement. If an exclusive block is required (see above), MBEW is blocked exclusively until the end of update processing by the block entry EM07W. The following block entries exist:

User Shared Table Block argument
USER1 EM07W 003XX11 0001
USER1 X EM07M
003XX11 00010001MARD0001 L01
USER1 X MARC 003XX11 0001
USER1 X MBEW 003XX11 0001
USER2 X EM07M 003XX11 00010001MARD0001 L01
USER2 X MARC 003XX11 0001
USER2 X MBEW 003XX11 0001

The additional exclusive block EM07W has the effect that USER2 cannot post the goods movement as long as the movement has not been posted by USER1.

Other users can still enter goods movements for this material since the shared lock is still set.

If no exclusive block is required, the indicator shared is set for the block entry EM07W. Several users can post the goods movement at the same time if no-one has blocked the material exclusively.

Change system parameters in customizing

The material block setting is not embedded in the Customizing application. In the standard system, the exclusive material block is implemented in the same manner as up to now.

You can set the material block using Transaction omji. The configuration appplies to all plants in a client.