Your BOM Is the Design
July 6, 2026 · 3 min read · SiteOps Command
The spreadsheet that says 480 feet of Cat6 and the drawing that says otherwise are both wrong the moment someone edits one and not the other. A bill of materials you maintain by hand is a bill that is wrong by lunch.
The fix is not a better spreadsheet. It is to stop keeping the BOM as a separate thing at all.
The BOM is a projection, not a document
When the bill of materials is generated from the devices placed on the plan, it is not an artifact you maintain — it is a view of the design. Move a camera, add a switch, reroute a cable, and the BOM updates, because it was never a copy in the first place. There is no version of it that can disagree with the drawing.
From placement to a complete bill
Placement drives a deterministic chain. Each stage derives from the one before it, so nothing is hand-counted and nothing is forgotten.
The devices you place set the hardware; the hardware needs cabling to reach it; the cabling needs conduit and pathways; the endpoints need switching and ports; the links need transceivers; the software needs licensing; and the cameras need storage. Skip a step by hand and the install finds it. Derive it and the install matches the quote.
Cable by physics, not by eyeball
Cable lengths come from real routes — with the vertical drops and service loops that a straight line on the plan ignores — not a rough distance times a fudge factor. It is the same discipline as the coverage physics: the number is computed from the building, not guessed, so the footage you bill is the footage you pull.
Why re-keying is the enemy
The moment the BOM lives in a different tool than the design, they drift. The install bills for cable that was never pulled; the as-built shows a switch that has since moved; the renewal quotes hardware that was swapped a year ago. One shared model removes the seam — the drawing, the bill of materials, and the as-built are the same thing seen from different angles. The BOM is the placed devices; it cannot drift from the design.
A short checklist
- Generate the BOM from the plan, not a spreadsheet.
- Let cable lengths come from real routes, not a multiplier.
- Re-run the BOM after every design change — it costs nothing.
- Keep one model so the drawing, the BOM, and the as-built agree.
A bill of materials that derives from the design is one you can stand behind at the quote, the install, and the renewal. See the SOW & BOM and project lifecycle pages, why six separate tools make this drift, or the integrator workflow; or book a demo on your own plan.
Frequently asked
- How do you generate a bill of materials from a design?
- Place the real devices on the floor plan; the platform derives the hardware, cabling, pathways, switching, transceivers, licensing, and storage from what is placed. The bill of materials is a projection of the design rather than a separate document to maintain.
- Why does a hand-keyed BOM drift from the drawing?
- Because it is a copy. The moment the design changes and the spreadsheet does not (or the reverse), the two disagree — and the install, the invoice, and the as-built inherit the error.
- How are cable lengths calculated?
- From the actual routes on the plan, with vertical drops and service loops, not a straight-line distance times a fudge factor. Real routes give a bill you can hold the install to.