How to control BOM readiness before a panel build

Most BOM problems are revision problems wearing a disguise. Engineering changes a device — a larger MCCB for a revised fault level, a different contactor after an obsolescence notice — but a saved copy on someone's drive never gets the update. Procurement orders to the old list. Kitting picks to the old list. The build goes together to a revision nobody is officially working to any more.

Short-kits are the other half. The panel is released to keep the floor busy, with two or three lines still on order. The builder gets most of the way through, reaches the missing gland plate or the back-ordered relay, and stops. Now you have a bay full of part-built panel and an operative on the next job — and when the part lands, someone has to remember where the build was left and pick it back up cold.

Both failures share a root cause: no single, current BOM tied to the job, and no honest view of whether the parts are actually in before release. Fix those two things and most of the stalls disappear.

The BOM sets everything downstream. It drives what gets ordered, what gets kitted, what the builder fits, and — through the device schedule — whether the finished panel matches what was designed and quoted. The panel only matches its verified design, and the quote, if the revision it was built to is the current one. Get the wrong contactor rating or the wrong protective device in on the strength of a stale list, and you have re-work at test, or worse, a discrepancy nobody catches until FAT.

It also fixes the earthing and protective-conductor arrangement the downstream installation relies on, so those decisions are made in design rather than improvised on the bench. A BOM that is right and under control is the cheapest quality control you will ever run. A BOM that drifts turns into scrap, credit notes and slipped dates.

One current BOM revision, bound to the job, is the whole game. Track changes against it so you can see what moved and why, and make that the single version everyone orders and picks from. There should be no ambiguity about which list is in force — no spreadsheet on a shared drive competing with a print in a folder.

When engineering issues a revision, procurement and kitting should see it, not chase it. That means the change is visible on the job, not buried in an email thread. Long-lead items already on order to a superseded line get flagged, not silently left wrong.

Readiness is a portfolio question, not a per-job one. You need to see, across every live job, which panels are fully kitted and which are waiting on parts — so you release the ones that can actually be finished and hold the ones that can't.

The point is to catch the gap before the build starts, while there is still time to chase a supplier or re-sequence the floor. Discovering a shortage mid-build is the expensive version: labour already committed, a bay occupied, and a part-built panel to protect and remember.

Before a job goes to build, one person should be able to answer yes to every line below. If any answer is no, the panel isn't ready — hold it, or release it knowingly with the gap named and owned.

Take a shop building around 30 panels a month. A form-separated distribution board is released on a Monday to keep a builder occupied. The kit looks close enough — one incoming ACB is still on order, four weeks out, but the thinking is the build will reach it later.

By Wednesday the builder is at the incoming section and stops. The panel is two-thirds wired, so it can't be handed to another job, and it can't ship. It sits in a bay for the rest of the four weeks. When the ACB lands, a different operative picks it up, spends half a day re-reading the drawings to work out where the first left off, and finishes it. The date has already slipped, and the floor lost a bay for a month.

Run the same job through a readiness check and it never releases on the Monday. The missing ACB shows on the long-lead watch-list at order time, the panel stays held, and the builder starts a fully-kitted job instead. When the ACB arrives, the board is released and built straight through. Same parts, same people — the difference is checking readiness before release rather than discovering the gap mid-build.

This isn't about replacing full inventory accounting. It's BOM revision control and material readiness against each panel job — the operational view that tells you whether to start a build. It complements a stock or MRP system rather than duplicating it.