Only consume pre-assembled

A sub-assemblySub-AssemblyA reusable assembly block that composes into bigger BOMs. Define it once, include it in any BOM. At execution time, Assemblified expands the sub-assembly into its own components recursively. Read more → normally cascades: once its pre-assembledPre-Assembled InventoryStock of finished sub-assemblies and BOM items that have already been built and are sitting on the shelf. When a work order needs a sub-assembly, it draws from pre-assembled inventory first and only builds fresh ones if the shelf comes up short. Read more → shelf is exhausted, demand falls through into its materials and nested sub-assemblies. Only Consume Pre-Assembled turns that off for one assembly — sales demand stops at it.

When the flag is on, that sub-assembly contributes only its pre-assembled stock to anything sales-related. Orders draw from its shelf and nothing below it is ever consumed; availability is computed from its shelf alone. Deliberate builds (work orders, assembly builds) are unaffected — they still pull materials as before.

On this page

• The flag, briefly
• What “stops here” means
• Max buildable vs. Sellable
• When the shelf runs short (deficits)
• Cancel & refund behavior
• Multi-layer trees
• How it differs from the BOM-level “only sell pre-assembled” setting
• Common gotchas

The flag

Each sub-assembly has its own Only Consume Pre-Assembled toggle, in the Assemble Settings card on the assembly-bill detail page. It’s independent of the parent BOM and of every other sub-assembly.

• On. Sales demand draws only from this sub-assembly’s pre-assembled stock — the materials below are never consumed, and availability is computed from the shelf alone.
• Off. Demand beyond the pre-assembled stock cascades into this sub-assembly’s materials and nested sub-assemblies (the normal behavior).
• Default: Off.
• Subscription: Enhanced. The Switch renders disabled with an “Enhanced Plan” badge on the Free tier.

What “stops here” means

With the flag on, every sales/order/availability traversal that reaches this sub-assembly treats it as a leaf: it contributes its pre-assembled quantity and the walk does not descend into its components.

Concretely, for a flagged sub-assembly S that an order needs N of:

• N is taken from S’s pre-assembled shelf.
• S’s materials and nested sub-assemblies are not touched.
• Availability calculations count only S’s shelf as S’s contribution — never the capacity its materials could build.

The decision is per-node. A layer-1 sub-assembly with the flag off still passes its remainder down; if a layer-2 sub-assembly underneath has the flag on, the cut happens there instead. Each node decides for itself.

What is unaffected

Only sales and order demand respect the cut-off. Deliberate physical builds — work orders, the assemble-bench, and building pre-assembled stock — still consume materials normally. The rule of thumb: fulfilling an order honors the flag; building stock never does, because building has to consume the materials it’s made from.

Max buildable vs. Sellable

Once a tree contains a flagged sub-assembly, “how many can I make?” has two different answers, so the UI shows both numbers wherever a BOM or assembly’s capacity is displayed — the detail pages, both list pages, and the nodes in the BOM tree view.

• Max buildable — units you could physically build. Materials inside flagged assemblies still count here.
• Sellable — what orders and availability actually use. A flagged assembly contributes only its pre-assembled stock; its materials are never counted.

Example. A sub-assembly is set to Only Consume Pre-Assembled and holds 5 pre-built units; its materials could build 50 more.

• Max buildable = 55 (5 on the shelf + 50 from materials).
• Sellable = 5 (only the shelf counts).

Hover the Max buildable N (Sellable M) label anywhere it appears for this same explanation inline.

Tip

For a BOM with dynamic adjustment on, the Sellable number is what gets pushed to Shopify — so the storefront never offers capacity that a flagged sub-assembly’s materials could theoretically build but that you’ve chosen not to sell against.

When the shelf runs short (deficits)

If an order needs more than a flagged sub-assembly has on its shelf, demand does not fall through to materials — that’s the whole point. Instead the full demand is consumed from the pre-assembled shelf, which is allowed to go negative.

A negative shelf is an honest record of a deficit: “this many units were sold against this assembly beyond what was physically on the shelf.” It’s not clamped to zero, and it’s not hidden — the negative balance shows in the per-location pre-assembled values.

You resolve a deficit the same way you’d top up any shelf: build more and adjust the pre-assembled count up, which moves the balance back toward zero and beyond.

Cancel & refund behavior

Restores are symmetric with consumption. When an order against a flagged sub-assembly is cancelled or refunded, the cascade halts at that sub-assembly (exactly like the keep-assembled halt): the full quantity is restored to its pre-assembled shelf, and nothing below is restored — because nothing below was consumed in the first place.

If the consumption had driven the shelf negative, a partial restore lifts it partway back (e.g. −5 then a +3 restore lands at −2, not clamped to 0), keeping the deficit math honest.

Don't toggle mid-order-lifecycle

The return side is flag-driven, not a replay of what happened at order time. If you flip Only Consume Pre-Assembled on (or off) between an order and its cancellation, the restore follows the flag’s current state, which can break the symmetry. Change the flag when there are no in-flight orders against the assembly. This is the same class of caveat as the keep-assembled flag.

Multi-layer trees

Because the decision is per-node, you can mix flagged and unflagged sub-assemblies in one tree:

BOM B
  └── Sub-assembly S        (flag OFF — cascades)
       ├── Raw R1
       └── Sub-assembly T   (flag ON — stops here)
            └── Raw R2

For a sales order of B:

• S has the flag off, so demand beyond S’s shelf passes down to R1 and T.
• T has the flag on, so demand reaching T is taken from T’s shelf only — R2 is never consumed, and T’s contribution to “sellable” is T’s shelf alone.

Each flagged node is an independent cut; the walk continues normally everywhere else.

How this differs from the BOM-level setting

These two are easy to confuse — different scope, different effect:

	Only sell pre-assembled quantities	Only Consume Pre-Assembled
Lives on	a BOM (Assemble Settings)	a sub-assembly (Assemble Settings)
Effect	caps the BOM’s own Shopify availability at the BOM’s pre-assembled shelf	stops sales demand at this sub-assembly inside a tree — materials below are never consumed or counted
Documented in	BOM settings → #6	this page

They’re complementary and can be used together: a BOM can cap its own availability while a sub-assembly deeper in its tree independently refuses to cascade into its materials.

Common gotchas

• Sellable, not buildable, is what sells. When the flag is on somewhere in a tree, the storefront-facing number is the Sellable figure. The higher Max buildable number is informational — it’s the physical ceiling, not the offer.
• Deficits are real, not errors. A negative pre-assembled balance on a flagged assembly means it sold beyond its shelf. That’s by design; top the shelf up to clear it.
• Setting the flag late doesn’t rewrite history. Past orders processed with the flag off cascaded normally. Flipping it now affects future orders only.
• Builds always consume materials. Don’t expect a work order or assemble-bench build to “respect” the flag — those are deliberate builds and always pull materials.

Where to next

• Pre-assembled stock — the shelf this flag draws from, and how to adjust it.
• Keep-assembled cascade — the other Assemble-Settings flag that halts the return-side walk.
• Nesting & execution — how expansion works, and where this cut-off lands in it.
• BOM settings → Only sell pre-assembled quantities — the BOM-level cousin of this flag.