Bill of Materials & Build Tracking
Produce finished goods from raw components in BizBooks Pro. Define each assembly's recipe once, run a build when stock gets low, and the software cascades the inventory and cost postings automatically.
What is an assembly?
An assembly is an inventory item you manufacture from other inventory items rather than purchase. Each assembly carries a bill of materials — the list of component items and the per-unit quantity needed to produce one finished good.
Running a "build" tells BizBooks Pro to:
- Reduce each component's on-hand quantity by what was consumed
- Increase the finished assembly's on-hand quantity
- Calculate the rolled-up component cost and stamp it onto the finished stock layer
- Post the cost movement between inventory sub-accounts
Defining the BOM
- Open Lists → Items and create a new item of type Inventory Assembly
- Fill in name, SKU, sales price, income account, and COGS account
- In the Bill of Materials section, click + Add Component
- Choose a component item (must already exist as inventory or non-inventory) and enter quantity per finished unit
- Repeat for each component
- Save
Running a Build
- Go to Inventory → Build Assemblies
- Pick the assembly to manufacture
- Type how many units to build
- BizBooks Pro displays the component requirement and checks current stock
- If any component falls short, the build is rejected with a shortage list
- Click Build to commit
Builds are atomic — every component decrement and the assembly increment land together in a single database transaction. A failure rolls back the whole build with no partial state.
Reversing a Build
The Unbuild action reverses a build run:
- Drops finished-assembly stock
- Restores each component's stock at the original cost
- Posts the reverse cost movement
How Cost Is Calculated
BizBooks Pro determines assembly cost as the sum of (each component's cost × the BOM quantity), evaluated at the moment of the build:
- The roll-up cost is stamped onto that batch's inventory layer. Future component price changes do not retroactively recost stock you already built.
- The assembly's standard cost field recalculates whenever the BOM is changed, so quoting tools reflect current cost.
Behind the Numbers
A build doesn't change total inventory value — it just shifts dollars between inventory sub-accounts:
| Account | Debit | Credit |
|---|---|---|
| Inventory — Finished Goods (Assembly) | Sum of component costs | |
| Inventory — Raw Materials (per component) | Component cost × quantity used |
When the finished assembly is sold, the normal sale entry posts: COGS debit / Finished Goods credit, at the stamped batch cost.
Reports & Tracking
Watch your manufacturing flow with these views:
- Inventory Valuation Summary — shows finished goods alongside raw materials
- Build History — full audit trail of build / unbuild events with quantity, cost, and user
- Low Stock Alerts — fires for either components or finished goods