1. Data is deleted or cleaned up: historical data in SAP system will occupy a lot of storage space, so it will be cleaned up during system operation to release storage space. If you delete or clean up the data in the historical inventory table, the data will be incomplete.

2. Unsuccessful data transmission: In the SAP system, when data is transmitted from one module to another module, there may be unsuccessful data transmission. If the data in the historical inventory table is not successfully transmitted to the corresponding module, the data will be incomplete.