Reorder points without a forecasting tool

You do not need forecasting software to decide when to reorder. For most SKUs, three inputs from your own data are enough: how fast it sells, how long the supplier takes, and how much buffer you want against a bad week.

The formula

Reorder point = average daily sales × lead time in days + safety stock.

A common way to set safety stock is z × standard deviation of daily sales × √(lead time), where z reflects the service level you want (about 1.65 for roughly 95% of cycles without a stock-out, assuming fairly normal demand).

Illustrative: 12 units/day on average, a 20-day lead time and a daily standard deviation of 4 units give a safety stock of 1.65 × 4 × √20 ≈ 30, and a reorder point of 12 × 20 + 30 = 270 units.

Where it breaks

• Seasonal or promotional spikes: compute averages from comparable weeks, not the whole year.
• New SKUs with little history: borrow the velocity of a similar product and review weekly.
• Unreliable suppliers: use the lead time you actually observe, including its variation, not the quoted one.