Negative postings to MVER table

Question

Dear SAP guru's,
I am trying to simulatie the MVER table trough the MSEG material movements. I've accomplished 95% accuracy through the use of T156-KZVBU en MSEG-KZVBR fields. I'm still missing the posting of some material movement.
For example the following line:
MSEG-MENGE=500
MSEG-BWART=602
MSEG-SHKZG=S
MSEG-KZVBR=V
T156-SHKZG=S
T156-KZVBU=G
This has been posted as negative consumption (-500) in MVER. Although it is adding stock (S) this usually gets posted as positive consumption (like a 101 movement with KZVBR=V).
What am I missing? Which fields are used to further determine the consumption posting to MVER?
With kind regards,
Nanne Sluis

Answer 1

If it helps somebody, I wrote a little tutorial, documenting my research (no guarantees on completeness; and feedback welcome):
How does MSEG-INSMK work, or better: How are the different stock types being updated in MARD/MARDH/MCHB/MCHBH/u2026
According to SAP note 368259, MSEG-INSMK cannot be used to determine which stock type fields in history tables are getting updated by the MSEG row. Hence, we investigated the approach on how stock type quantities are getting updated:
Required SAP tables:
-     MSEG
-     MKPF
-     T156M
-     T156F
Maybe required:
-     T156SC
-     T156SY
-     T156W
-     T156X
The following tables need to be considered and joined accordingly:
Example:
The following tables/fields need to be joined together to retrieve the information which history table fields of stock types are getting updated based on which material movement. Beware that multiple fields can get updated within one transaction; hence the joins can multiply rows. It makes sense to first create a table of T156M / T156F values and pivot it. Afterwards it can be used within the material movements flow:
1.     Table MSEG (Document Segment: Material): Starting point
MSEG-BWART = 555          (GI scrapping blocked)
MSEG-SHKZG = H          (Credit posting)
MSEG-SOBKZ = u2018u2019          (no special stock)
MSEG-BUSTM= u2019MS01u2019           (Posting string for quantities)
MSEG-ZUSTD_T156M= u2018u2019      (Stock Type Modification (Read from Table T156M))
2.     Table T156M (Posting String: Quantity): Result after Join
T156M-BUSTM=u2019MS01u2019          (Posting string for quantities)
T156M-ZUSTD=u2019u2019           (Stock type modification)
T156M-CNT02=u201801u2018           (Consecutive counter in ATAB tables for inventory management)
T156M-SMARD=u2018LS1u2018           (Segment string) Updating table MARD
T156M-SMCHB=u2018CD1u2018          (Segment string)  Updating table MCHB if batches are used
3.     Table T156F (Fields in Quantity String): Result after Join
T156F-SEGST=u2018LS1u2018           (Segment string)
T156F-CNT02=u201801u2018           (Consecutive counter in ATAB tables for inventory management)
     T156F-FELDV=u2019MARD-SPEMEu2018  shows the updated history table field
The following fields need to be joined, basically:
MSEG inner join T156M ON
     MSEG.BUSTM=T156M.BUSTM
       and     MSEG.ZUSTD_T156M=T156M.ZUSTD
T156M inner join T156F ON
     T156M.SMARD=T156F.SEGST
     T156M.CNT02=T156F.CNT02
Additional Information:
MSEG-BUSTM (Posting string for quantities)
Key for the automatic determination of the stock fields that:
u2022     Have to be checked when a goods movement is entered (availability check)
u2022     Are updated following a goods movement.
T156M-ZUSTD (Stock type modification)
Serves to differentiate between quantity updates carried out for the various stock types.