Inventory app for a Shopify auto parts store with 2,000 SKUs

A parts catalogue is wide and uneven. Oil, filters, wiper blades, pads and bulbs leave the shelf every week. A hub assembly that fits three model years leaves twice a quarter. Shopify shows you the quantity on hand for each variant and says nothing about the rate it is going out, so the watching falls to a habit instead of a system.

Usually one of three:

• A spreadsheet rebuilt on a Sunday, accurate for about four days.
• A mental list of the twenty parts that actually matter, which works until the twenty-first sells out.
• A sales report read backwards, after a customer asks for a filter you do not have.

Three things make this harder in parts than in a short catalogue. Two thousand variants is too many to scan, so the long tail goes unwatched by default. Demand is lumpy: the same catalogue holds a consumable that sells daily and a hard part that sells on a schedule nobody controls. And lead time is not one number, because a local distributor restocks in two days while an import sits for six weeks, and the wait usually belongs to the supplier rather than to the individual part.

Running out of the fast consumable is the expensive one. The customer buying pads buys the fluid and the cleaner in the same order, and if one line is missing they buy all three elsewhere.

A reorder point is only as good as the window you measure sales over. Restoc calculates it from a sales velocity window of 7, 14 or 30 days and the lead time behind each SKU. The window is the real choice, and in a parts catalogue it cuts both ways.

A 7-day window reacts fast. A run on wiper blades after the first cold week shows up almost immediately. But a part that sells four times a month looks dead inside seven days, so its reorder point sits far too low and the alert arrives after the shelf is empty.

A 30-day window is steady. Slow-moving fitment parts get a sensible average and stop flickering. But a consumable that doubles in a fortnight is averaged against three weeks of quieter trade, so the alert lands later than you want it.

Restoc lets you set the window store-wide, which is enough for most catalogues. On Pro you can override the window on a single SKU, so the oil and the wipers can be read over 7 days while the model-specific hard parts are read over 30. That is the feature a parts store pays the Pro price for, more than the SKU cap.

Safety stock, for the lines that sell in bursts

An average assumes demand arrives evenly. Parts rarely oblige: a quiet fortnight on a filter and then a workshop order for nine. So the reorder point also takes a store-wide safety stock percentage, a cushion added on top of the demand expected during the lead time. Set it once for the store, and the units it adds show as their own column on the dashboard, in the weekly reorder report and in the CSV, so you can see what the cushion is costing you in stock rather than guess at it.

Worth saying plainly: this is a velocity calculation, not a forecast. It reads what your store has actually sold and the wait you told it to expect. It does not predict a season before the season starts showing up in orders.

A parts store evaluating inventory apps deserves the limits up front.

• One location per store. Every plan is one location. If your stock sits across a shop floor and a separate warehouse in Shopify, Restoc reads a single location today.
• No demand forecasting. It calculates from sales already recorded, the lead time you give it and the safety stock percentage you set. Seasonal planning stays with you.
• Supplier lead times, not a supplier record. Vendor names arrive from your Shopify products and each one carries a lead time. There is no supplier contact, no price list, no order history and no supplier import or export.
• One safety stock percentage for the store. The cushion is store-wide. Pro's per-SKU override applies to the velocity window, not to safety stock.
• No purchase orders. It tells you what to order and how much; placing the order with your distributor happens where it happens now.
• No barcode scanning and no receiving flow. This is reorder alerting, not a warehouse system.
• Web app only. No mobile app, no browser extension. The alerts come to email and Slack, which is where a phone is useful anyway.

If you want the scale question on its own terms rather than the parts-catalogue version, the page on stores running 1,000 to 2,000 SKUs covers it, and the pricing page lays out all three tiers side by side.