An assortment is a set of deliberate inventory roles, not a collection of every available product. A useful plan explains why each SKU occupies shelf space, how much coverage it needs and what evidence will determine whether it stays.
Give every SKU a role
Core items have repeat demand and deserve dependable availability. Companion items support a category or a common customer need without requiring the same depth. Test items enter in controlled quantities for a defined review period. Exit items are being reduced and should not be reordered automatically.
The role belongs to the exact SKU or variant. A broad product family can contain one core variant and several test variants.
Calculate weeks of supply
Weeks of supply = available on-hand units ÷ average weekly unit sales.
If 48 available units sell at an average of 12 per week, the item has 4 weeks of supply. If 24 units sell at 2 per week, it has 12 weeks. The second item has fewer units but much more time coverage.
Use available units rather than a physical count that includes damaged, reserved or quarantined stock. Record the sales window and exclude out-of-stock periods when they would distort the average.
Set a range, not one universal target
A target should reflect lead time, order pack, sales stability, shelf space and the consequence of a stockout. A core item may need enough coverage to bridge normal replenishment plus a reasoned buffer. A test item may have a maximum exposure rather than a replenishment target.
| Role | Primary question | Useful review signal |
|---|---|---|
| Core | Can normal replenishment protect availability? | Stockouts, lead time and weeks of supply |
| Companion | Does it add useful choice without excess depth? | Sales contribution and shelf capacity |
| Test | What result and review date justify expansion? | Sell-through during the test window |
| Exit | How will remaining units be handled lawfully? | Age, remaining quantity and action owner |
Respect case-pack and shelf constraints
A target of 20 units is not directly orderable if the supplier case contains 60. The buyer can accept the higher coverage, combine purchasing decisions where allowed, or reconsider whether the SKU fits the assortment. Calculate the pack relationship with the case pack guide before setting the target.
Use a defined test plan
For a new item, record the test quantity, start date, placement, expected review date and decision rule. Avoid changing several factors during the test without noting them. A temporary promotion or unusual display can make the result hard to compare with normal selling conditions.
Review related metrics together
- Weeks of supply shows time coverage at the observed sales pace.
- Sell-through compares units sold with units made available during a defined period.
- Reorder point determines when replenishment should begin.
- Inventory age shows how long units have remained in stock.
No single measure decides the assortment. High sell-through with repeated stockouts may understate demand. High weeks of supply after a large delivery may be temporary. Slow sales with old inventory require a different response from slow sales on a newly received test.
Document the decision
At each review, keep the SKU, role, current stock, sales window, weeks of supply, next action, owner and next review date. This makes decisions consistent across buyers and prevents an old test item from becoming permanent by accident.
Review categories without forcing every item to behave alike
Category totals can reveal whether shelf space or inventory dollars are concentrated, but replenishment decisions still belong at the exact SKU level. Compare the roles within a category: too many test items can consume the capacity needed by core items, while a category made only of core items may lack a controlled way to learn. Set a limit for simultaneous tests based on available space and the team’s ability to review them.
When a product changes role, record why. A companion item can become core after sustained repeat sales; a core item can move to exit after demand changes. The decision should reference a defined observation period rather than one unusually busy or quiet week.
Use the reorder-point guide for core replenishment and the inventory-aging guide for excess coverage. The catalog helps identify exact product records; authenticated ordering details should be checked when a buying decision is ready.
Content notes
A measured way to assign core, companion and test roles, calculate weeks of supply and review shelf capacity without letting one short sales spike drive the assortment.
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Reviewed by: MWHQ GOODS Editorial Team