Guides
What Shopify Inventory Planning Looks Like in 2026
Planning has moved from a spreadsheet you rebuild every cycle to a forecast-driven loop that recomputes itself — here's what changed, and what the new loop actually looks like.
The spreadsheet didn't break — the job changed
The classic reorder sheet was a good tool. On-hand quantities pasted in from the store, a velocity column derived from last period's sales, a hand-tuned buffer, and a column of quantities to send to suppliers. It was legible, auditable, and it worked — because the job it was built for was small, slow, and stable.
What broke wasn't the arithmetic. It was the assumptions underneath it. A spreadsheet is a snapshot: correct at the moment you pasted the numbers in, quietly stale by the time you act on it. That's tolerable when the catalog is short, the supplier is predictable, and one sales channel accounts for everything. Each of those conditions has loosened. The sheet still computes what it always computed; it just no longer describes the business by the time the decision gets made.
Four pressures that moved planning forward
Four forces, mostly independent, pushed planning past what a periodic rebuild can carry.
Lead times got longer and less predictable. Overseas manufacturing turns order-to-arrival into a window measured in weeks or months, and that window moves. A plan built around a single assumed lead time has no way to express "usually six weeks, sometimes nine" — so the risk lands as a surprise rather than as a number.
Inventory became a visible financing decision. Stock is capital held in a warehouse. When money is expensive, over-ordering stops looking like prudence and starts looking like what it is — a loan you made to yourself, at a rate. Two failure modes now bracket every reorder: stock out and lose the sale, or over-buy and lock up cash you needed elsewhere. Optimizing only against the first is how planning quietly became expensive.
The decision grain got finer. Multichannel selling multiplies SKU-location combinations, and variant proliferation means the thing you actually order is rarely the thing you report on. Aggregate a product across its variants and you get a number that's right in total and wrong in every particular — the size that sells out and the size that sits are averaged into one comfortable middle.
Demand started moving faster than a monthly review can observe. A cycle that samples the business once a month sees a trend after it has already run for weeks. A launch, a creator post, a competitor going out of stock — the signal arrives and decays between reviews.
What a forecast-driven planning loop looks like now
The shape that replaced the rebuild has four properties. It's continuous rather than periodic — the plan recomputes as sales, stock, and incoming quantities change, so there's no window where the numbers are known-stale. It's projection-based rather than snapshot-based: the question isn't "what did we sell last period" but "what will this sell over the period I'm buying for," which is the only horizon a purchase order actually cares about. It runs at variant grain, because that's the unit that gets ordered, received, and stocked out. And it's scenario-tested rather than single-number: a forecast you can't interrogate is a guess with better typography. You should be able to ask what happens if the trend runs hotter, or what the history looks like with past stockouts excluded — since days you couldn't sell depress recorded sales and make raw history understate real demand.
Laid side by side, here's the planning loop, then and now:
| Dimension | Spreadsheet-era loop | Forecast-driven loop |
|---|---|---|
| Cadence | Rebuilt on a calendar | Recomputed as data changes |
| Basis | Last period's sales as a snapshot | A projection over the period you're buying for |
| Grain | Product-level, aggregated by hand | The variant you actually order |
| What you review | Every row | The exceptions worth acting on |
| Output | A number you retype into a PO | A draft order you approve or adjust |
From assembling numbers to reviewing decisions
The subtler shift is what the planner's hour is spent on. In the spreadsheet era, most of it went to assembly — exporting, pasting, reconciling, recalculating — and only the last few minutes to judgment. That ratio is backwards, and it gets worse as the catalog grows, because assembly scales with row count while judgment doesn't.
Exception-based review is how mature teams keep a large catalog reviewable: rank by what's at stake, act on the head of the list, and let the rest stay as-is until something changes. Combine that with a plan that arrives pre-drafted and the human job becomes the thing only a human can do — deciding whether the suggestion is right given the supplier conversation, the marketing calendar, and the cash position that no dataset knows about.
Where Assisty fits in the 2026 loop
Assisty is built for that loop rather than for the rebuild. It forecasts what each product — and each variant — will sell over the horizon you choose, flags what runs out, and explains why the numbers move. What-if scenarios apply instantly: ask what happens if sales trend up 20%, or exclude the weeks you were out of stock, and the forecast and the reorder needs update in front of you, no spreadsheet copies.
| Step | What Assisty does |
|---|---|
| Project | Forecasts predicted sales per product and per variant over the period you pick — buying decisions happen at variant level, so do the forecasts |
| Test an assumption | What-if scenarios apply instantly; the forecast and the reorder needs update in front of you, with no spreadsheet copies |
| Spot the exceptions | Marks which items run out before the period ends and which are overstocked; at-risk items carry straight into the Smart Buying Table |
| Draft the order | Every SKU gets an AI-suggested quantity computed from sales velocity, lead times, and incoming stock — rounded to your case sizes and capped at your maximum stock levels |
| Commit | Splits your selection into one PO per supplier and asks which location receives it; every change shows a was→now chip with per-row undo, and nothing is committed until you create the order |
The Smart Buying Table surfaces what matters ranked by money at stake — items that run out before a reorder can land, capital tied up in overstock — and every finding carries its one-tap fix. You can reshape the plan by talking to it: fit-to-budget defers the least-urgent items and shows exactly what got cut. The loop closes where it should, on a decision you approved rather than a number you retyped.