Inventory management questions
Direct answers to the questions ecommerce brands actually ask about stock levels, reordering, forecasting, and operations.
Inventory levels
- How much inventory should I keep on hand? You should keep enough inventory on hand to cover demand over your replenishment lead time plus safety stock for variability, consistent with your target service level and cash limits. Practically, this means setting per-SKU target days of supply and safety stock instead of guessing a fixed number of units.
- How do I know if I am overstocked? You are overstocked when your on-hand and inbound inventory materially exceed forecast demand over the next replenishment cycle. In practice, the fastest warning signs are unusually high days of supply, turnover below your target range, weak sell-through, and aging SKUs that keep appearing in your inventory report month after month.
Reordering
- When should I reorder inventory? You should reorder inventory when projected days of supply will fall below your lead time plus safety stock buffer. In practice, use the reorder point calculator at /calculators/reorder-point-calculator and your supplier lead times to trigger purchase orders a full lead time before you run out.
- How much inventory should I order from each supplier? You should order enough inventory from each supplier to cover forecast demand over the next replenishment cycle plus safety stock, while staying within cash and storage limits. Use EOQ from /calculators/eoq-calculator as a starting point, then adjust for supplier MOQs, discounts, and lead time risk.
- How do I account for lead time when reordering? You account for lead time by setting reorder points that cover expected demand during the full lead time plus a safety stock buffer for variability. Use the reorder point and safety stock calculators, then adjust for average supplier lead time variance of around 20–30% for overseas manufacturers.
Forecasting
- How do I forecast inventory demand? You forecast inventory demand by turning your Shopify order history into forward-looking sales estimates per SKU, then adjusting for growth, marketing, and seasonality. Start with recent average daily velocity, overlay known events like BFCM where demand jumps 2–4×, and use tools like Synplex to automate updates as new data arrives.
- How do I account for seasonality in inventory planning? You account for seasonality by separating baseline demand from predictable peaks and troughs, then planning inventory and POs specifically for each period. For example, many brands see BFCM demand run 2–4× above average daily velocity, so they temporarily increase forecasts, safety stock, and order quantities ahead of that window.
- How accurate are my inventory forecasts? Your inventory forecasts are as accurate as the gap between predicted and actual sales at the SKU and period level, typically measured with metrics like MAPE. By comparing forecast versus actual each month and tracking these errors, you can see which products are well-modeled and which need better data or simpler assumptions.
Financial KPIs
- How much cash is tied up in my inventory? Cash tied up in inventory equals your on-hand units multiplied by unit cost, plus the ongoing carrying cost of holding that stock. To make the number useful, split it by fast movers, slow movers, and dead stock, then compare it to your turnover target and annual carrying cost benchmark of 20–30%.
- How do I reduce inventory carrying costs? You reduce inventory carrying costs by holding less excess stock, turning inventory faster, and preventing slow SKUs from accumulating. Since carrying cost typically equals 20–30% of unit cost per year, the biggest wins usually come from tighter reorder logic, cleaner SKU rationalization, and faster action on overstock.
Operations
- What is purchase order management? Purchase order management is the process of planning, creating, approving, tracking, and receiving supplier orders so inventory arrives in the right quantity and time. For Shopify brands, it links demand forecasts, cash constraints, and lead times to the Admin → Purchase orders workflow and your inventory adjustments when stock lands.
- How do I manage inventory across multiple locations? You manage inventory across multiple locations by planning stock by node, not just by total company inventory. That means defining each location’s role, reviewing on-hand by location in Shopify, moving stock with transfers before shortages hit, and replenishing each node based on its own demand and transfer timing.
- How do I decide which products to discontinue? You should discontinue products when they consistently consume cash and space without earning enough margin or strategic value in return. The cleanest decision framework combines GMROI, turnover, sell-through, demand predictability, and whether the SKU still plays a real role in bundles, acquisition, or category credibility.
- Do I need an inventory planner or can I manage with spreadsheets? You can manage with spreadsheets for a while, but once inventory decisions depend on faster updates, multiple locations, or repeatable purchase-order logic, a dedicated planner becomes the safer system. Spreadsheets are common, but they break down when demand, lead times, and inventory workflows change faster than a team can update cells.