Once a product has a bill of materials, Stockroom can treat it as something you make instead of something you order. Three pieces work together: a per-product Restock by setting, a Components readiness strip on the pages where you decide, and Create build actions wherever you are.
Restock by
On a product page with a recipe, the replenishment row offers Restock by: Buying (the default) or Building. It is a per-variant stock setting and travels in the stock-settings CSV as restock_by.
The Components strip
Components: Available / Partial / Missing tells you whether a build could be made from stock right now at that location, after open builds have claimed theirs. It shows on each build, on the Restock page beside a suggested quantity, and under the product title on the Products list.
Restock
Products restocked by building gather in a To build group with its own Create builds button - one draft build per ticked line.
A buildable product still bought shows Build instead on its supplier row, which opens New build prefilled.
Components that open builds need appear as Needed for builds on their own Restock rows, and the remaining output of an open build covers a suggestion like an open purchase order does.
Create build from anywhere
Products list - a Build action on each row opens New build with the recipe selected.
Shopify product and variant pages - More actions > Create build, and the Stockroom - Builds block you can pin to the product page shows how many you can build and the open builds.
Shopify order page - More actions > Create build lists the order's products that have a recipe; each becomes its own draft build linked to the order.
Out-of-stock rule - if you use the automatic out-of-stock purchase orders, a short product that is restocked by building gets a draft build instead of a PO.
Shopify Flow - a Create build action, plus triggers for build created, finished, blocked, overdue, assigned and stage changed (see Automate Stockroom with Shopify Flow).
Good to know
Everything raised for you is a draft - you review and record it.
Readiness is Stockroom's math over your Shopify stock; it never reserves anything in Shopify.
Sub-assemblies are consumed as finished stock - Stockroom does not explode a recipe into a recipe. Build the inner product first, then the outer one.