SAP MM 預留單據的歷史修改記錄？
在筆者眼里，SAP系統是一個高度嚴謹的軟件系統。用戶在SAP系統里的相關操作，系統都會做記錄。用戶對於系統的相關單據的增刪改，SAP系統都有保留change history,並且可以很方便被人查詢這些change history。但是筆者發現，並不是所有單據的修改，SAP系統都提供很好的查詢change history的方式，比如Reservation單據。
如下的預留單ITEM，筆者有將數量由80改成了81，
筆者試圖找到該預留單據的change history, 如同查詢其它單據修改記錄的方式，找遍了MB23事務代碼里的諸多菜單，都找不到。
上網查資料，發現SAP標准系統是不保留預留單據的change history信息的。看來SAP保持增刪改的痕跡以方便后續追溯的嚴謹風格，執行的並不徹底！當然SAP系統對於任何單據的修改都有記錄在表CDHDR & CDPOS里，但是標准系統里，這2個表里的數據，對於業務用戶，並不能方便的查詢。
SAP NOTE 1927840 供參考。
1927840 - Change log for reservations
Symptom
Create a Purchase Requisition with reference to a reservation and later make changes to delivery date,for example, in transaction ME52N. The field RESB-BDTER is updated with the delivery date changes but no change log is written.
You would like to record changes made to reservations.
Reproducing the Issue
Call a reservation in transaction MB22.
Make a change to the reservation.
Save the changes.
There is no change log.
Cause
This is standard SAP system design.
Resolution
In enhancement MBCF0007 you find user exit EXIT_SAPMM07R_001.
This user exit is called directly after the COMMIT WORK statement in MB21/MB22 and contains information related to the old and new item details in table RESB. You could use this user exit to update the reservation changes to a custom table.
The standard change log table are CDHDR & CDPOS. If you were to use these as part of a custom development to capture reservation changes you would have to pay special attention to performance as these tables are often very large.
2019-04-28 寫於蘇州市。