The quick answer
Go to Lists > Supply Chain > Bills of Materials and click New Bill of Materials. Enter a Name, restrict the BOM to the assembly and Save. Then click Create New Revision, add the components with their BOM Quantity and save the revision. Last, edit the BOM, add the assembly on the Assemblies subtab with Master Default checked, and Save. The assembly item's Bills of Materials sublist then lists the BOM with its Current Revision.
The screenshots show sample data. Person and operating-company names are fictional. Use your own records and values when following the steps.
Before you start
You need Advanced Bill of Materials and Assembly Items enabled, permission to create bills of materials and revisions and to edit assembly items, and the assembly item and every component item already created. The Subsidiary field and the location restrictions appear only when your account has those features. In this example the WB-300 workbench has no BOM yet, and the components are TP-48 Maple Tabletop, LG-90 Steel Leg and BT-8 Hex Bolt M8 x 40. Menu paths and fields can vary with your account's features and role.
01. Open the list and start a new BOM
Go to Lists > Supply Chain > Bills of Materials. The list shows each BOM, and the Used on Assembly column says whether it is attached to an assembly. None of the BOMs here is for WB-300. Click New Bill of Materials.
02. Name the BOM and restrict it to the assembly
Type the Name, WB-300 BOM. Clear Available For All Assemblies, which opens Restrict To Assemblies. Click the chooser beside that field, click WB-300 under Click Selection to Add so it appears under Current Selections, and click Done. Leave Available For All Locations checked, so the BOM is not restricted to particular locations, and keep Birchwood US selected under Subsidiary. Leave Use Component Yield cleared for now. Step 3 comes back to it. Click Save.
The saved BOM shows Restrict To Assemblies WB-300, but Used On Assembly is cleared and the Revisions subtab has no records. Restrict To Assemblies only says which assemblies may use the BOM. It does not attach the BOM to WB-300, and the components are stored on revisions, so the BOM has no component list until it has one.
03. Create the first revision
On the Revisions subtab, click Create New Revision. The form opens in its own window. Enter the Name WB-300 Rev A and leave Effective Start Date and Effective End Date blank. On Components, select TP-48 Maple Tabletop and click Add, then LG-90 Steel Leg, then BT-8 Hex Bolt M8 x 40. Each new line starts at Component Yield 100.0%, BOM Quantity 1 and Quantity 1.
Change BOM Quantity to 4 on LG-90 Steel Leg and to 16 on BT-8 Hex Bolt M8 x 40, the amounts each workbench uses. Then try Component Yield. Set it to 80.0% on the steel leg and Quantity changes from 4 to 5, because 4 divided by 0.80 is 5. Set it back to 100.0% and Quantity returns to 4. Description and Quantity are filled in by NetSuite, so you don't type them.
In this account Quantity recalculated on the line even though Use Component Yield is cleared on the BOM. That check box decides whether the yield is applied to downstream requirements such as work orders and planning. It stays cleared in this walkthrough, so check it on purpose, and confirm how your account behaves, before you rely on yield.
Click Save. The window closes and the BOM lists WB-300 Rev A with no effective dates. A revision with no dates has no start or end boundary. Revisions of one BOM can't overlap, and a gap between them leaves dates with no active revision, so give each revision a start date if this BOM will get more.
04. Assign the BOM to the assembly
On the BOM, click Edit and open the Assemblies subtab. Choose WB-300 in Assembly, check Master Default, click Add, then click Save.
Used On Assembly is now checked, and the Assemblies subtab lists WB-300 with Master Default Yes. An assembly has one Master Default BOM, so checking it here clears the designation on any other BOM that held it for WB-300.
05. Confirm it on the assembly item
Click WB-300 on the Assemblies subtab to open the item, then open its Manufacturing subtab. The Bills of Materials sublist lists WB-300 BOM with Current Revision WB-300 Rev A and Master Default Yes. The date columns are blank because the revision has no dates. A revision shows as current only when it applies today under the assembly's BOM control, so a BOM whose revisions are all future-dated or expired shows No Active Revision instead.
Check the result
- The Revisions subtab of WB-300 BOM lists WB-300 Rev A.
- Used On Assembly is checked on the BOM.
- The Assemblies subtab lists WB-300 with Master Default Yes.
- The WB-300 item's Bills of Materials sublist shows WB-300 BOM with Current Revision WB-300 Rev A.
Common questions
Does a bill of materials need a revision before it is useful?
Yes. The Bill of Materials record holds the name, the subsidiary and which assemblies and locations may use it. The components live on its revisions. A BOM needs a revision that applies on the relevant date before it gives a work order a component list.
Does Restrict To Assemblies attach the BOM to the assembly?
No. Restrict To Assemblies and Available For All Assemblies decide which assemblies are allowed to use the BOM. The BOM is attached to an assembly on its own Assemblies subtab or in the Bills of Materials sublist on the assembly item's Manufacturing subtab.
What does Used On Assembly mean?
It is normally a read-only check box that is checked once the BOM is attached to at least one assembly. It doesn't say the BOM is the assembly's Master Default. A BOM can be attached without being the default.
Does a revision need an Effective Start Date?
No. The form accepts both dates blank, and a revision with neither date has no date boundary. For a BOM you will keep revising, give each revision a start date. Revisions of the same BOM can't overlap, so end an open-ended revision before you add the next, and remember that a work order picks its revision by Production Start Date.
How does Component Yield change the quantity?
The line shows Quantity as BOM Quantity divided by Component Yield. At 100.0% the two are equal, and 4 at 80.0% gives 5. Whether the yield-adjusted quantity is applied to work orders and planning depends on the Use Component Yield check box on the BOM and on the manufacturing features in your account.
What happens to the Master Default BOM an assembly already has?
An assembly has one Master Default BOM. Checking Master Default on a different BOM for the same assembly generally clears the designation on the earlier one. A BOM can't be both the Master Default and a Default for Location BOM for the same assembly, and a Default for Location BOM takes precedence at its location.
Why does my assembly still show no bill of materials?
Check that the BOM is attached to the assembly, that the BOM and its revision are active, that the revision applies on the relevant date, and that the subsidiary and location fit. Also look for a Default for Location BOM that overrides the Master Default. Then open the item's Manufacturing subtab to see what NetSuite lists.