Inventory & Channel Sync
How do I manage thousands of Shopify SKUs and variants without inventory planning falling apart?
Planning inventory for a large catalog without tracking every single variant by hand.
Last updated September 16, 2026
Plan at the style-color. Do not plan every size.
Plan at the style-color parent
A 200-style line with eight sizes is 1,600 variants. The parent you actually purchase is Crew / Navy. Cover target is 28 days. Size curve is 5 / 10 / 20 / 25 / 20 / 12 / 6 / 2. You place one buy of 800. Variants inherit 40, 80, 160, 200, 160, 96, 48, 16. Treat each size as its own reorder point and the week disappears into XS versus XL while Navy Crew is already late at the factory. Own a size-level reorder only when sell-through breaks the curve (XL is gone in 8 days, XS still has 40) and you can still name the parent buy. Colorways, kit components, and marketplace aliases do the same thing. They look like new SKUs. They are not a new buy.
Split the work with ABC cuts
At a few thousand SKUs you cannot stare at every row. Split the work with three ABC cuts, not one letter reused for everything. Sales-value ABC, the sum of sale lines over 90 or 180 days, not list price times units, tells you where the money is. Pick velocity tells you what to slot and count. Inventory-value ABC, quantity times cost, tells you what is sitting on the shelf. That last cut matters when a kit finished good is A and the component is C. A free gift-with-purchase or a packing insert will steal A slots if unit volume drives the cut. Keep the default class as a reference and maintain your own fast-mover flag when it lies.
365 days hides a seasonal brand. Recalculate. New SKUs have no class until they sell, so they vanish from counts and replenishment if you filter A, B, or C. Give launches a temporary A. A items get tight records, frequent counts, a real reorder point, and a forward bin. C items get simplest control, rare counts, deep storage, and bigger buys. Do not cycle-count eight thousand sizes. Count the A styles and the components that actually leave the bin.
Point marketplace aliases at one parent
One catalog across Shopify, Amazon, and wholesale is still one catalog. Crew / Navy Medium has 40 on-hand and 28 days of cover on Shopify. The Amazon listing CREW-NVY-M-AMZ does not point at that parent, shows 6, and a planner places 200. You now hold 240 of one size and the curve is shot. You bought twice. Do not forecast every variant from last week's Shopify export. Roll demand up, place the buy, then break sizes from a curve. If you cannot name the planning parent, the days of cover, and the class in one line, that SKU is not plannable yet. A five-thousand-SKU catalog across marketplaces only stays honest when most rows inherit a plan instead of owning one.
Connect Claude or ChatGPT to your Fulfil data with the Fulfil MCP, then run this prompt on your own numbers.
You are the inventory lead for a Shopify brand with thousands of variants. Here is: sku, parent_style, color, size, is_alias, alias_parent, channel, last_90d_units, last_90d_sales_amount, on_hand, unit_cost, pick_count_90d, current_abc, days_since_launch, current_rop, days_of_cover, size_curve_pct. [paste] Produce: 1. The planning parent for each row (style-color, not every size). Flag SKUs that own a ROP they should inherit. 2. Sales-value ABC, inventory-value ABC, and pick-velocity ABC. Show where they disagree. 3. Marketplace aliases that do not point at the same parent (risk of a double buy), with the extra units that buy would create. 4. New or no-class SKUs that would drop out of a count, and a temporary A list. Do not treat every size as its own planning universe.
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