Bill of materials

The bill of materials — the BOM — is a materials list computed from the layout you have generated. It is a view of the plant: the BOM tab (Ctrl+4) shows the list as a table in place of the plot, every cell in it is editable, and the finished list prints as the Bill of Materials pages of the Detailed Project Report.

It is not a separate document you keep by hand. The quantities are read out of the plant, so a layout that changes and is generated again produces a different list. What you add on top of that — extra line items, corrected descriptions, remarks for a procurement team — is yours, and it stays until you ask for the list to be rebuilt.

The BOM view

Click the BOM tab, or press Ctrl+4. Generate a layout first: the list is computed from a placed plant, and there is nothing to compute before one exists.

The table takes the whole area under the view header. The left column hands its inputs over to a green banner ● Bill of Materials with an Exit BOM button, and under it the BOM TOOLS panel; Exit BOM hands the column back to the stage tabs. The status line reads "BOM Mode ON — double-click any cell to edit. It prints on its own page in the PDF." The view tabs and the tools beside them are described on Views.

The list is part of the session, so it is saved into the project file along with the inputs, the layout and your sketch edits, and comes back when the project is reopened. See Projects.

The five columns

The table has a fixed set of columns, in this order.

Quantity and Unit are deliberately separate. A line counted in numbers and a line counted in metres sit in the same table without ambiguity, which matters as soon as cables and structures appear on the same list.

BOM TOOLS

The panel in the left column holds everything that acts on the list.

The hint under the buttons says what the panel is for: "The main table is the automated BOM. Load Template opens it in a separate window; edit it there, then replace the plant BOM with it (used in the PDF)."

Hide Layout & Energy Summary carries a label older than the interface: what it hides is the chip row, not a table. Untick it and the chips come back; nothing is discarded.

What rebuilding does

⚙ Rebuild from Layout is not a refresh that merges. It recomputes the whole list from the current plant and puts that in place of what was there.

That is the behaviour you want in one specific situation and not in any other:

• Rebuild after you have changed the layout — moved a control room, drawn an obstruction, added or deleted tables by hand, turned cable calculation on, run the cleaning tool — and you want the quantities to match the plant again.
• Do not rebuild once you have started editing the list for real. Finish the layout first, rebuild once, then edit. The order costs nothing and saves the work.

If you need both — a fully edited list and a set of current quantities to check it against — export the edited list to a spreadsheet before rebuilding, then compare the two outside the application.

Editing a cell

Double-click any cell and type. Every column is editable, including the computed quantities — so a figure you overwrite is a figure you own from then on, and it stands until the list is rebuilt.

Three edits are worth making even on a list you otherwise leave alone:

• Descriptions. The computed text is generic. Replacing it with the designation your organisation buys against turns the list into something a supplier can quote from.
• Remarks. Cable specifications, connector types, structure grades and finishes — the detail the layout has no way of knowing.
• Missing line items. Anything the plant's geometry cannot imply. Read the computed list against your own material take-off and add what is not in it.

For a starting point written for a reference plant of the same design, load the built-in template rather than typing from scratch. See Materials list templates.

Where the quantities come from

Two sources, and understanding the split tells you which figures move when you change the design.

The plant's own counts. Everything the layout has placed and measured is already known — the module count, the full and half tables or tracker units, the inverter control rooms, the string inverters or string monitoring boxes, the lightning arresters, the street lights, the piles, and the cable and trench lengths. These are the same figures the Summary view reports, so the two never disagree. See Summary columns.

The topology rules. Some quantities are not placed on the ground and have to be derived from a rule instead. The combiner box and transformer counts are the clear case, and they follow three rules:

ACCB is the AC combiner box; IDT is the inverter duty transformer. The reason these three numbers matter here rather than only in the electrical design is that the single-line diagram's automatic build uses the same rules. Build the diagram from the plant and it groups inverters into combiner boxes, boxes into transformers and transformers onto the medium-voltage panel by exactly the counts above — so the diagram and the materials list agree on how many of each there are. See Building a diagram from the plant.

What the list contains

The rows come out in a fixed order. A row whose quantity would be zero is left out altogether, so a short list is not a fault — it means the plant has none of that item.

Four things change that list:

• A tracker plant carries Tracker (Full) and Half Tracker in place of the two table rows.
• A central-inverter plant carries SMB (String Monitoring Box) and Central Inverter in place of String Inverter, adds DC Cable (SMB → Central Inverter), and its second trench row is the DC trunk trench — there is no AC leg. See Choosing a design mode.
• Running without cable calculation leaves every cable and trench row at zero, so they drop out.
• Not placing a main control room drops rows 15 to 19, from the switchgear panel down to the room itself.

The cleaning robot fleet

Rows 22 to 24 appear only after you have run the cleaning tool. Run 🤖 Robotic Module Cleaning on the Tools tab, decide which wide gaps you will bridge, and click its Add n robots + m bridges to BOM button. The fleet then feeds both the Summary view's Cleaning robots row and this list. Until you do, there is no fleet on the list at all.

That is deliberate. A cleaning fleet is a purchase decision with a bridge count attached to it, not something a layout implies, so the list never carries a fleet you did not ask for. See Robotic module cleaning.

Exporting the list

Two exports on the tools panel, both of the list on screen rather than the computed one — whatever you have edited is what is written.

These are separate from the report. Export ▾ ▸ Export Detailed Project Report, in the view header, writes a Word document that already carries the materials list as its Bill of Materials annexure, paginated across as many pages as the list needs, alongside the drawing, the summary and the diagram — and Export PDF (with Piles) carries the same pages while the pile overlay is on. Use the standalone buttons when you want the list on its own; a purchasing department rarely wants the engineering drawing attached to it. See The Detailed Project Report.

What the list is, and is not

State this to whoever receives it, because it sets what they can do with it.

• It is a materials list, not a priced bill of quantities. There is no rate column, no amount column and no total. Pricing happens after the export, in the spreadsheet.
• The descriptions are generic. They describe the item, not a supplier's catalogue part. Nothing here is tied to a make, a model or a stock code until you type one in.
• It follows from a layout, so it inherits the layout's assumptions. Cable quantities exist only if cable calculation was on for the run; a fleet exists only if you sized one; arresters exist only if you asked for them. A missing row on this list is usually a setting rather than an absence.
• Nothing is checked against a standard. Quantities are counts and lengths, not a verified schedule of material.

A working order

The list is cheapest to produce if the plant is finished before you start editing it.

Where to go next