Quantity per board vs order quantity: panels, attrition and MOQ

Boards are often made and assembled several to a panel, so a build runs in whole panels. With 4 boards to a panel, 100 boards need 25 panels. Ordering 98 boards needs 25 panels as well. A quote may count boards or panels, so ask which, and say which you mean when you ask. The designator count and the BOM quantity do not change: they stay per board.

Some parts are lost to machine set-up, rejects and short reel ends, small passives most of all. Assemblers often state the overage they want, especially on parts you supply; the percentages here are examples. Sellers then sell by the pack. A minimum order quantity (MOQ) is the smallest amount a seller will sell, and parts come on reels or in trays and tubes, so what you buy is rounded up to the pack. In the table, the 0.1 µF line needs 400, overage makes 440, and the 100-piece pack rounds that up to 500. Prices follow the order quantity; see BOM cost rollup in Excel.

Keep three quantities apart and name the columns so nobody reads one as another: qty_per_board in the BOM, qty_needed for per board times boards, and qty_order after attrition and rounding. The BOM you send for a quote carries the first, with the build quantities stated beside it. Rework, test and field returns use parts outside the build quantity, so if you want spares, add them to the order quantity on purpose and say so.

• Overwriting the BOM quantity. An order quantity in the qty column breaks the designator check for the next person who opens the file.
• Panels read as boards. A quote for 25 panels is 100 boards on a 4-up panel. Mixing them up changes the buy by that factor.
• Ordering DNP parts. A total that includes DNP lines buys parts that are never placed. See DNP in a BOM.
• Double overage. You add a margin and the assembler adds its own. Agree who adds it.
• Rounding down. There are no fractional parts. Always round up.
• Ignoring MOQ and pack size. The line cannot be bought at the quantity needed, and the quote changes.

BOMParser keeps the per-board side honest. It checks every line's quantity against its designator count, leaves DNP lines out of the part totals, and compares the document's stated total with the sum. It does not calculate order quantities, attrition, minimum orders or panels; do that in your own sheet. Convert a file on the BOM to CSV page; pricing lists the plans. Free: 1 file per day, up to 10 pages, no account. Files over 10 pages are converted up to page 10 on the free allowance; a page code converts the whole file, up to 150 pages.