Safety-stock reservations

Assembly BOMs support safety-stock reservations with exactly the same mechanics as a finished good’s bill. Use the Reservations tab on the assembly BOM page to create, edit and release reservations per location.

You can also do it for several bills at once: on the Assembly BOMs list, tick rows and use the bulk bar’s Inventory → Reservations → Create or Release.

For the full lifecycle — creating a reservation, editing the target, the two release modes (restore materials globally, or convert held materials into pre-assembled stock), failure handling and edge cases — see:

→ Bill of materials → Safety-stock reservations

What is different for an assembly BOM

Nothing material. The reservation expands the assembly’s BOM recursively down to materials, exactly as a finished good’s reservation does, so a reservation on an assembly that itself contains nested assemblies still resolves to a flat list of materials.

The one subtle difference is that an assembly BOM has no Shopify variant. Converting its reservation to pre-assembled stock increments the assembly’s pre-assembled shelf; the Shopify-side push that the finished-good path runs for its variant is skipped, because there is no Shopify product to update. The “Reserved as safety stock” column on materials still tracks holds against assembly reservations identically.

That also means an assembly BOM can be reserved at any of your locations. A finished good has to be stocked at the location before it can hold a reservation there, because it is a Shopify product with inventory set up per location, and if it is not, the check blocks the row rather than offering to stock it for you. An assembly BOM is not a Shopify product: its pre-assembled stock can sit anywhere, and a location that has none yet simply starts at zero. The availability check therefore never asks you to “activate” an assembly BOM at a location, and never blocks one for not being stocked there.

A location rule on an assembly BOM does not block a reservation either. On a finished good, a bill that a rule has switched off at a location cannot hold a buffer there; an assembly BOM’s reservation is only ever about its own components and its own shelf, so it goes ahead.

Everything else about the check is the same: it is required before creating a reservation, it flags materials that are not stocked at the location (with an offer to activate them in Shopify), a material the BOM draws from a different location is measured and held at that location and labelled with it, “Create anyway” covers stock shortfalls only, and changing the location or a unit count means checking again.

Tip

Reservations earn their keep at the assembly level when a shared building block needs guaranteed availability for the finished goods above it. Hold a buffer of N units of the assembly with a reservation, then convert it to pre-assembled stock in batches as your build cadence allows.

Where to next

• Bill of materials → Safety-stock reservations — full mechanics.
• The assembly BOM page — where the Reservations tab sits.
• Pre-assembled stock — the shelf that convert-to-pre-assembled feeds.
• Nesting & execution — how an assembly BOM reservation’s recursive resolution lines up with the same recursion at order time.