The quick answer
Check Phantom on the subassembly's Purchasing / Inventory subtab, under Inventory Management. That sets the default, so also confirm the subassembly's line on the parent's bill of materials revision and work order has Item Source Phantom. When it does, the work order lists the subassembly once, then adds its own components as indented lines underneath. Build the parent from that work order with Create Build. The build consumes the subassembly's components directly. It doesn't take the subassembly from stock, and nobody has to build it on a separate work order first.
The example is a garden cart. A GC-210 Garden Cart takes 8 hex bolts, a steel axle, a bed panel and 2 WA-08 Cart Wheel Assemblies. Each wheel assembly is 3 hex bolts, a rim and a tire, and the plant never keeps finished wheels on the shelf. They get put together on the cart line. The walkthrough builds 12 carts at Fresno Plant with zero wheels in stock. The screenshots use sample data, and the person and company names are fictional.
Before you start
You need the Assembly Items and Work Orders features, and Multi-Location Inventory if you build at a specific location. Both the parent and the subassembly need a bill of materials with a revision that's effective on the order date; the example uses Advanced Bill of Materials. It also uses a standard work order that isn't WIP, 100% component yield, and items with no lots, serial numbers, bins or inventory statuses. If yours use them, the build needs Inventory Detail on the consumed component lines. Your role needs access to the Bill of Materials Inquiry, assembly items and BOM revisions, and permission to enter work orders and assembly builds. The date has to fall in an open posting period.
Phantom is a default, not a lock. It sets the Item Source NetSuite uses when the item goes onto another assembly's bill of materials or work order. If someone changed that line's Item Source to Stock or Work Order, the phantom won't expand. The same item can still be built and stocked on its own when you want it to be.
01. Review the multilevel bill of materials
Go to Transactions > Manufacturing > Bill of Materials Inquiry. Pick the Subsidiary and the Assembly, here GC-210 Garden Cart, and keep Location - All -, so the stock columns cover every location. NetSuite fills in Bill of Materials Garden Cart BOM, the revision Garden Cart BOM - Rev B and today's Effective Date. Leave Top Level Only cleared so you see every level.
Level 1 is the cart itself: 8 hex bolts, an axle, a bed panel and 2 wheel assemblies. Under WA-08 Cart Wheel Assembly, level 2 lists the wheel's own parts. BoM Quantity per Assembly is per wheel (3 bolts, 1 rim, 1 tire). Quantity per Top Level Assembly multiplies through to one cart, so 2 wheels need 6 bolts, 2 rims and 2 tires. WA-08 shows 0 on hand.
02. Check the Phantom setting
Click WA-08 Cart Wheel Assembly in the inquiry and open the Purchasing / Inventory subtab. Under Inventory Management, Phantom is checked. That's the setting that makes WA-08 come in as a phantom on the cart's work order.
Mark Sub-assemblies Phantom is checked too, but it does something else and isn't needed here. It treats assemblies inside the item where it's checked as phantoms. The wheel contains no assemblies, so on WA-08 it has no effect. You'd normally use it on a parent or a work order, and it stays cleared on the cart's work order below, so the Phantom setting on WA-08 is what drives the result.
03. Enter the work order
Go to Transactions > Manufacturing > Enter Work Orders. Choose Subsidiary Ridgeway Wagon Works US, Location Fresno Plant and Assembly GC-210 Garden Cart.
NetSuite may warn that WA-08 Cart Wheel Assembly has only 0 available for commitment across all locations. Whether it appears, and its exact wording, depends on your commitment settings. Here it's expected, because the WA-08 line is supplied as a phantom and the wheels won't come from stock. Click OK, then confirm the line's Item Source is Phantom. If the warning names one of the real components instead, take it seriously.
Bill of Materials fills with Garden Cart BOM and Bill of Materials Revision with Garden Cart BOM - Rev B, the revision effective on the order's production start date. Check both rather than assuming. Enter Quantity 12 and set Status to Released.
04. Review the exploded lines and save
On the Items subtab, the cart's own parts come first: Hex Bolt 96, Steel Axle 12 and Bed Panel 12. WA-08 Cart Wheel Assembly is one line of 24 with 0 available. Beneath it, indented, are the wheel's parts: Hex Bolt 72, Steel Rim 24 and Pneumatic Tire 24, each with stock at Fresno Plant. The bolts appear twice, 96 for the cart and 72 for the wheels, for 168 in total. If your form shows the Item Source column, the WA-08 line reads Phantom.
Click Save. WO1147 saves as Released with Buildable 12 and Built 0, even though Fresno Plant holds no wheel assemblies. Buildable follows the components that will actually be consumed, along with your location, commitment and unit rules. Zero stock of a phantom doesn't hold it back.
Further down, the saved order's Items subtab shows each line's Average Cost (a custom form may hide this column): 0.20 for the hex bolt, 6.40 for the axle, 14.50 for the bed panel, 2.10 for the rim and 4.35 for the tire. WA-08 has no cost of its own on this order.
05. Create and save the build
Click Create Build. A new Assembly Build opens with Assembly GC-210 Garden Cart, Location Fresno Plant, Quantity to Build 12 and Created From Work Order #WO1147. Projected Value is 439.20 in this example, NetSuite's estimate from the order's quantities and average costs: 96 bolts, 12 axles, 12 bed panels, then 72 more bolts, 24 rims and 24 tires. Nothing is costed for WA-08. The posted amount can differ, so check GL Impact on the saved build.
On the Components subtab, the cart's bolts, axle and bed panel show their Quantity On Hand. The WA-08 row shows 24 with no Quantity On Hand and no Inventory Detail, because no wheel assemblies are taken from stock. The 72 bolts, 24 rims and 24 tires beneath it are.
Click Save. The build saves as ASSYB0391 for 12 GC-210 Garden Carts.
Check the result
- The saved build shows the WA-08 line with its component lines indented beneath it. Column layout can differ on your form.
- The consumed quantities are 168 bolts (96 plus 72), 12 axles, 12 bed panels, 24 rims and 24 tires.
- The subassembly's own on-hand quantity didn't change, and no separate build exists for it. The recording doesn't open the item or GL Impact, so check both on your own build.
If a phantom didn't expand on your work order, look at the line's Item Source first and change it back to Phantom. A work order keeps the lines it was created with, so a later change to the item or the BOM doesn't rewrite an existing order. Reselect the parent assembly, or create a new work order, to pick up the change.
Common questions
What is a phantom assembly in NetSuite?
It's an assembly item that groups components on a bill of materials without being built and stocked on its own first. When a parent uses it as a phantom, NetSuite pulls the phantom's components into the parent's work order and build. Here, WA-08 Cart Wheel Assembly groups 3 bolts, a rim and a tire for each wheel on the garden cart.
What's the difference between Phantom and Mark Sub-assemblies Phantom?
Phantom sits on the subassembly's item record and makes that item default to Item Source Phantom wherever another assembly uses it. Mark Sub-assemblies Phantom works one level down: on a parent, BOM or work order, it marks the assemblies inside it as phantoms. Checking it on WA-08 doesn't make WA-08 a phantom, and since the wheel has no assemblies inside it, it does nothing there.
Does the assembly build consume the phantom or its components?
Its components. The build for 12 carts consumed 72 bolts, 24 rims and 24 tires through the WA-08 row, and that row has no Quantity On Hand or Inventory Detail because no wheel assemblies came out of stock. The component inventory goes down and the finished carts go up; the phantom gets no posting of its own. The walkthrough doesn't open GL Impact, so check the accounts on your own build.
Why does the work order warn that the phantom has 0 available?
The work order still lists WA-08 as a line, 24 wheel assemblies for 12 carts, and there are none in stock, so the commitment check flags it. That's expected when the line is supplied as a phantom. Click OK, confirm the line's Item Source is Phantom, and look at the indented component lines instead.
Why didn't my phantom expand on the work order?
Check the line's Item Source. If it says Stock or Work Order, NetSuite treats the subassembly as a normal component and doesn't add its parts. A work order also keeps the lines it was created with, so if you changed the item or the BOM afterwards, reselect the parent assembly or create a new work order to load the change.
Can a phantom assembly still be stocked?
Yes. Phantom is a default for how the item is supplied inside other assemblies, not a ban on building it. You can still build WA-08 into inventory on its own if you ever need finished wheel assemblies on the shelf.
What does Quantity per Top Level Assembly mean in the Bill of Materials Inquiry?
It's how much of a component one finished top-level assembly needs, after multiplying through every level. Each cart uses 2 wheels and each wheel uses 3 bolts, a rim and a tire, so the inquiry shows 6 bolts, 2 rims and 2 tires per cart. A work order for 12 carts scales that to 72, 24 and 24.
Do phantoms work with WIP work orders?
The phantom's components still feed the parent's production, but a WIP work order is completed with component issues and completions rather than the single Create Build used here. Check how those WIP transactions treat the phantom lines in your account, especially with routings, lots, serials or bins.