SAP Note 21482 - Weight/volume calculation is inexact

Symptom:

The weights in an SD document are either extremely inexact or are zero.
Example: The weight in the material master is 1.4 kg/pc.
The quantity in the item was very small at first, e.g. 0.001. As a result, the weight was rounded off, e.g. to 0.001. If the quantity is changed to 1.000, the weight is increased proportionally to 1.000.

Cause and prerequisites

1. The weight can be manually overwritten. Therefore, qhen quantities are changed, the system always calculates in the ratio of old quantity to new quantity. The weight is only recalculated based on the material master weight if the initial weight was 0.
2. When a delivery schedule is involved, the weight is calculated from the schedule line quantity, not from the target quantity.

Solution
No solution is currently available, because there is no way for the system to distinguish whether the old weight was calculated automatically or was manually overwritten.