Buyer’s guide
From a supplier notice to a decision
Enter the actual offer
Use the supplier’s price advance, discount brackets, or avoided charge. Enter minimum purchases at cost before the discount. Add your normal order cycle and the credit period that preserves your payment discount.
Prepare one vendor line
Export 12–24 calendarized months. Include months with zero activity so the period is explicit. Supply current on-hand, on-order and cost consistently for each item; use the latest dated values. Keep different branches and vendor lines in separate analyses.
| Field | What to provide |
|---|---|
date | Transaction or period date, YYYY-MM-DD |
sku | Item identifier; preserve leading zeros |
qty | Nonnegative usage in the item’s stocking unit |
on_hand | Current on-hand quantity |
unit_cost | Positive current cost per stocking unit |
| Optional | on_order, pack_qty, vendor, line, backorder_qty, lost_sales_qty |
Use consistent units for quantity, cost and pack size. An item priced per hundred needs a per-unit cost. Negative returns need to be reconciled before import; the workbench does not silently treat them as demand.
Add dated availability
Provide one on-hand snapshot for every item and month, using columns date,sku,on_hand. Without complete availability history, a zero-usage month could mean no demand or no stock. The tool marks that uncertainty and shows an initial return when a final return cannot be scored.
Review the purchase and assumptions
Compare annualized return on added investment (ROAI) with your hurdle. Initial ROAI is before fill-in risk; final ROAI includes it. Check total and incremental cash separately, the item exclusions, and stock that could remain after 12 months. The worksheet is a review document; it does not submit an order.
What the return means
Return on added investment is an annualized rate on the extra inventory investment, after carrying costs. It is not margin, a guaranteed outcome, or a return on the entire order. Price advances save the increase on extra stock; a quantity bracket can improve the price on the normal order too. The baseline subtracts discounts the normal order already earns.
What the simulation assumes
Historical demand variability is characterized; future demand levels are not forecast. Items are treated as independent. Demand shifts, seasonality and correlated job demand can make realized outcomes differ from these estimates. The same data, assumptions and seed produce the same result.
File limits and privacy
One CSV per vendor line, up to 20 MB and 250,000 usage rows. The supported item limit is shown during import. Only settings and explicitly scoped staple choices can be remembered locally. Refreshing or leaving the workbench clears transaction data; download the memo and worksheet before you leave.