In practice, have you noticed that the results of "ABC Analysis for Shipping" and "ABC Analysis for Inventory" often do not match?
For example, if you aggregate one week of shipping and inventory data and perform analysis based on their averages, you will find that the item composition is completely different.
Why the Discrepancy?
A fast-moving item might be ranked "A1" in shipping but only "C" in inventory.
This happens when analysis is performed just before a new arrival, when only "Safety Stock" remains. Ironically, this occurs most frequently with high-rotation items.
Which one should we consider the "truth"? Since inventory exists to support shipping, the answer is clear.
The total count of items in each group may be identical between the two analyses, yet the specific items within those groups differ. This is a common trap in logistics data.
When real inventory data is converted into "stable operational inventory" by factoring in rules for maximum inventory days and safety stock days, the ranks for shipping and inventory finally align.
Conclusion: Current shipping trends are the primary driver, and inventory is merely the side that must be adjusted to meet those trends.