In this guide 6 sections
A small panel shop can run on Excel BOMs while jobs are few and one person holds every revision in their head. The limit arrives once jobs overlap, with stale BOM copies in the store, shortages found at the wiring bench and test records nobody can produce. Move revisions and tests first.
Why Excel works at the start
One sheet per job is quick to build, so you copy last year’s BOM for a similar motor control centre, edit the breaker ratings and print it. The owner knows each customer and each drawing.
With three or four panels in the shop, the wiring crew asks the owner whenever a terminal label or cable size looks unclear, and the answer is immediate. No system beats a person ten metres away.
That advantage fades slowly. You rarely notice the day it ends.
- Few concurrent jobs
- One person owns every drawing
- Repeat customers who accept small delays
- Test results kept on a signed paper sheet
Revisions are the first crack
The customer revises the single line diagram. The BOM sheet is updated. The copy emailed to purchase last week is not. The store issues the old breaker, the wiring crew builds to the old drawing, and nobody notices that two copies of one BOM disagree.
Excel has no concept of a current revision. File names like final, final2 and latest settle arguments only until someone saves over the wrong one on a busy Friday afternoon.
Panel software holds one BOM per job with revision history; a change flags the lines that moved, and purchase sees only the delta.
Shortages show up too late
A sheet lists what the panel needs. It does not know what sits on the shelf, what is on order, what other jobs have already claimed or when the next truck arrives. A busbar support is missing. The crew stands idle.
Software that reserves stock against each job shows the gap on the day the job is released, so purchase orders the enclosure before wiring starts. Lead times differ. An enclosure takes weeks. A terminal block takes a day. You buy the long items first.
Shortage lists also change the order of work. Build the kitted section first.
- Reserved stock per job
- Open purchase orders and promised dates
- Substitutes approved by the designer
- Items short at kitting, listed before wiring starts
Test records are where buyers push back
A buyer asks for the routine test record for panel PX-14; it should show insulation resistance, continuity of the protective circuit, functional checks and the checker’s name. Often it is a sheet in a drawer.
If a customer calls two years later about a tripping breaker, you need the as-built BOM and the test sheet side by side. Excel files and paper rarely sit together.
Software links the test checklist to the job, the BOM revision and the serial of the panel; the record is produced in a minute, not an afternoon.
How to move without stopping the shop
Do not copy every old sheet in. Start with the next new job. Build its BOM in the system, reserve stock against the job number, and run the test checklist there while the old sheet stays closed beside the keyboard.
Keep the Excel library for now. Import the assemblies you reuse most, such as a motor starter or a feeder section, as templates, and let the rest wait until a job actually needs them.
After the first three jobs, count the shortage surprises and the time spent finding records; that comparison tells you whether to go further.
Panel job release sheet
One page, used at job release. Blocks: job number and drawing revision, BOM revision and date, kitting status per line with shortage marked, and long lead items with promised dates. A test plan lists each routine check. Readings go in a column beside each check.
Open a blank worksheet to printQuestions owners ask
How many jobs before Excel stops being enough?
The count differs from shop to shop. The signal is overlapping jobs where more than one person edits a BOM, or where a revision reaches the store a day after wiring has begun.
Is panel software expensive to adopt?
Cost varies by scope. Starting with BOM revisions and test records on new jobs keeps the first step small and gives a clear before and after.
Can software handle customer-specific drawings?
Yes. The drawing file attaches to the job and its revision, so the shop and the store see the same current version.
Do we still need Excel afterwards?
Often for quick quotes and one-off calculations. The job record, stock levels and test sheets move into the system, and the sheet keeps only the quick quote arithmetic.