Build Assembly By-Products & Semi-Products Guide

How to record production that creates a main finished item plus additional usable output items.

Inventory & POS Manufacturing End-User Guide

Overview

Some production processes create more than one usable output. A build may produce one main finished item and also create secondary items such as reusable leftover material, waste with value, or an intermediate item used in another production stage.

Use by-products when these additional items should be added to inventory during the same Build Assembly transaction.

Example: A perfume build can create perfume as the main finished item, leftover oil as a by-product, and perfume base concentrate as an intermediate stock item.

Output Types

Output Meaning Recommended Setup
Main finished item The main item being produced by the assembly build. Create it as the assembly item selected in Build Assembly.
By-product A secondary output created during production, such as leftover material or a reusable side output. Create it as an inventory item and add it in the assembly by-products list.
Semi-product An intermediate item used in a later production stage. Create it as an inventory or assembly item. Add it as an additional output when it is produced in the same build.

Enable The Option

Path: Company / Options > Inventory
  1. Open the company options screen.
  2. Go to the Inventory settings.
  3. Enable Allow by-products for manufacturing.
  4. Save the options.
Note: If this option is not enabled, by-product entry areas may not appear in the assembly setup and Build Assembly workflow.

Create The Items

Create each output item before setting up the assembly.

Item Suggested Item Role
Perfume Main assembly item.
Leftover oil Inventory item used as a by-product output.
Perfume base concentrate Inventory or assembly item used as an intermediate output.

Set Up The Assembly

Path: Inventory > Assembly Components
  1. Open the main assembly item.
  2. Add the raw material component lines, such as oil, chemicals, bottles, labels, or other required inputs.
  3. Open the by-products area.
  4. Add each additional output item, such as leftover oil or perfume base concentrate.
  5. Enter either a fixed output quantity or a percentage of the main build quantity.
  6. Save the assembly setup.
Quantity choice: Use a fixed quantity when the output is always the same amount. Use a percentage when the output should change with the main build quantity.

Build The Assembly

Path: Inventory > Build Assembly
  1. Select the build date, store, and main assembly item.
  2. Enter the main build quantity.
  3. Review the raw material component lines that will be consumed.
  4. Review the by-product output lines that will be added to inventory.
  5. Confirm lot or serial details where required by your item setup.
  6. Save the build.

After saving, review stock movement to confirm that raw materials decreased and all output items increased as expected.

Costing Notes

By-product rows are useful for recording additional output quantities. If the business also needs separate cost tracking for each output, review the accounting requirement before deciding whether to use one build or multiple build stages.

Requirement Recommended Approach
Only the extra quantity must be recorded. Use by-products in the same Build Assembly transaction.
The intermediate item needs its own production cost and later consumption. Create the intermediate item as its own assembly item and use a separate Build Assembly stage.
The main item and by-products need a formal cost split. Define the costing policy with accounting before using the workflow for financial reporting.
Important: When multiple outputs have material financial value, confirm the expected costing treatment with the accounting team before posting live production.

Perfume Example

Production Part Example Item How To Enter It
Raw materials Oil, alcohol, chemicals, packaging Add these as normal assembly component lines.
Main output Perfume Select this as the main assembly item in Build Assembly.
By-product Leftover oil Add it in the by-products area with fixed quantity or percent output.
Semi-product Perfume base concentrate Add it as an additional output if produced in this build, or build it separately when it needs its own production stage.

Troubleshooting

Issue What To Check
The by-products area is not visible. Check whether Allow by-products for manufacturing is enabled and whether the user has access to assembly screens.
The by-product item is not available for selection. Confirm the item exists, is active, and is set up as an inventory-related item.
The output quantity is wrong. Review whether the row uses fixed quantity or percentage of the main build quantity.
The production process has multiple stages. Use separate assembly items and separate build records when each stage must be tracked independently.
The cost result is not what accounting expects. Review the costing policy and consider separate build stages for items that need their own cost tracking.