BOM for assembly quotes: what a quoting team needs to price a build

A quote has two halves, parts and labour. For parts, the team looks up each line by manufacturer and MPN, multiplies quantity per board by the boards, and prices the result at the matching break. For labour, it counts what the build must do: how many unique lines need feeder set-up, how many placements, how many through-hole joints. Assemblers weigh these differently, so ask which counts matter to yours.

A line the team cannot price becomes a question. A line it prices badly becomes a surprise later.

Turnkey means the assembler buys every part. Consigned, also called free-issue, means you supply some or all of them. Mixed builds are common: the assembler buys the passives while you supply a hard-to-source IC. Add a column that says who supplies each line. Consigned lines still need quantities and MPNs, and assemblers usually ask for extras to cover machine loss; see quantity per board vs order quantity. To price the parts side yourself, see BOM cost rollup in Excel.

The BOM says what to fit. Other files say where and how. Fabrication data, usually Gerber and drill files, defines the bare board. A placement file, also called a centroid or pick-and-place file, lists each designator with its position, rotation and board side. An assembly drawing shows polarity marks, orientation and special instructions, such as parts to fit by hand or areas to keep free of coating. A quote built from the BOM alone has to guess at all three.

• Revision mismatch. The BOM quoted is not the BOM built, or it does not match the board files. See BOM revision control.
• Wrong quantity basis. A per-panel or per-order quantity where per board was assumed prices the build at the wrong multiple.
• Descriptions with no ratings. CAP 10uF leaves out voltage, dielectric and size, so the assembler guesses or asks.
• No MPN on connectors and electromechanical parts, which cannot be priced from a value.
• Mechanical items forgotten. Screws, standoffs, heat sinks and labels have no designators and are easy to omit.
• Unavailable preferred parts. A quote built on a part nobody can buy is reworked when the assembler substitutes.

BOMParser turns a PDF BOM into a fixed-column CSV and checks it before it reaches a quoting team: quantity against designators, duplicate MPNs, lines with no MPN, DNP lines. The upload CSV (qty, mpn, manufacturer, ref_des) is a generic layout for tools that take those four columns, not any distributor's template. It does not request quotes or look up prices. Convert a file on the BOM to CSV page; pricing lists the plans. Free: one BOM every 24 hours, ten sheets or fewer, no registration. A free run stops at sheet 10 of a longer BOM. Redeem a code and the ceiling rises to 150 sheets.