Your inventory is part of the packing problem
When you already own cartons, the question is no longer just “what box size would work?” It becomes “what can I pack with the box types and quantities I actually have?”
In Packmetry’s existing-box workflow, available quantity is a real limit. If a carton type has one unit available, a plan cannot silently open a second carton of that type. A zero quantity means that carton cannot be used.
The existing-box workflow does not invent purchase cartons when your stock runs out. It works only with the carton types and quantities you entered.
Use multiple carton types when that reflects reality
Real stockrooms are rarely made of one perfect box size. Entering several carton types gives the solver a more realistic set of choices. A verified plan may use one type exclusively or combine different types when that is a better fit for the order.
This is also why carton quantity should be maintained carefully. A mathematically suitable carton is not a usable option if there is no stock available.
Hybrid is different from “have boxes”
Hybrid packing is useful when existing stock should be used first but buying additional cartons is acceptable for the remainder. It answers a different operational question from strict inventory-only packing.
In practical terms, the three workflows are:
- Need boxes: find suitable cartons for the items you need to pack.
- Have boxes: pack only into the stock and quantities you entered.
- Hybrid: use existing stock and cover the remainder when inventory is insufficient.
Review inventory usage, not only the 3D picture
A successful plan should tell you both how the items were arranged and what happened to your carton stock. The inventory summary is useful because it makes the operational consequence of the plan visible: what was used and what remains.
The 3D arrangement explains fit. Inventory usage explains the stock decision. Together they give a more complete view than either one on its own.