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Bills of Materials (item structure)

A Bill of Materials describes an item structure: which materials and in what quantities are required for production, as well as which by-products are generated.

In the system, a Bill of Materials is used as a source of planned norms: based on it, material and output lines are generated automatically in a manufacturing order.

Location​

Bills of Materials are usually available in the “Manufacturing” section (depending on your configuration — in Operations or Settings).

What a Bill of Materials is used for​

A Bill of Materials is used for:

  • automatically filling material lines in a manufacturing order;
  • calculating planned consumption and planned output;
  • generating by-products during production;
  • unbuild (disassembly) — usually using the same Bill of Materials;
  • analyzing the item structure and planned norms.

Bill of Materials card: main fields​

In the Bill of Materials card you typically set:

  • Number — Bill of Materials identifier;
  • Item — the item the Bill of Materials applies to;
  • Quantity and Unit of measure — the base quantity for which norms are defined (for example, 1 pc, 10 pcs, 100 kg);
  • Name — a free name/comment;
  • Default — indicates that the Bill of Materials should be selected automatically in a manufacturing order for this item;
  • Archived — indicates that the Bill of Materials is no longer used.

Important:

  • a Bill of Materials marked as default must be active (not archived);
  • if an item has a default Bill of Materials, it may be selected automatically when you choose the item in a manufacturing order.

Bill of Materials structure: tabs​

Components​

The “Components” tab contains material lines (what is consumed during production).

Each line usually contains:

  • Item (material/component);
  • Unit of measure;
  • Quantity — the consumption norm for the base quantity of the Bill of Materials;
  • Cost distribution coefficient — used when the Bill of Materials is used for unbuild (see below).

How to read component quantity​

Component quantity is defined for the base quantity of the Bill of Materials.

Example:

  • Bill of Materials quantity = 10 pcs;
  • component A = 2 kg.

This means: to produce 10 pcs of the item, you need 2 kg of component A.

If the manufacturing order is for 25 pcs, the component plan will be calculated proportionally: 2 × 25 / 10.

By-products​

The “By-products” tab defines by-products that are generated during production.

Each line usually contains:

  • Item (what is additionally produced);
  • Unit of measure;
  • Quantity — the norm for the base quantity of the Bill of Materials.

How by-product quantities are calculated in the order — see By-products.

Using the Bill of Materials in a manufacturing order​

Bill of Materials auto-selection​

If an item has a default Bill of Materials, the system may select it automatically when you choose the item in a manufacturing order.

Item consistency check​

In a manufacturing order, the system enforces that:

  • the order item must match the Bill of Materials item.

If they do not match, the order cannot be saved.

Generating lines from the Bill of Materials​

In the manufacturing order card there is an action to generate lines (for example, “Create Lines”).

For regular production:

  • Bill of Materials components generate material lines;
  • the order item generates an output line;
  • Bill of Materials by-products are added to output lines.

For unbuild (disassembly):

  • Bill of Materials components generate output lines;
  • the order item generates a material line;
  • Bill of Materials by-products are added to material lines.

For details about unbuild, see Unbuild (disassembly).

Cost distribution coefficient in the Bill of Materials​

Component lines in the Bill of Materials can store a cost distribution coefficient.

It is used for unbuild:

  • when unbuild lines are generated, coefficients from Bill of Materials components are copied to output lines;
  • then the total unbuild cost is distributed across output lines using these coefficients.

For details about cost distribution, see Costing: how it is calculated.

Versioning and relevance​

Recommendations:

  1. Do not edit archived Bills of Materials.
  2. When the item structure changes, create a new Bill of Materials (new number) and make it the default.
  3. Archive the old Bill of Materials so it is not selected for new orders.

Mass entry via tables (import/export)​

The system provides actions to import/export Bills of Materials and their lines to a spreadsheet file.

Typically, separate operations are available:

  • export/import Bills of Materials;
  • export/import components;
  • export/import by-products.

Typical scenario:

  1. Export a template.
  2. Fill in lines in the table.
  3. Import the file back.

Important: during import the system validates that items and Bills of Materials exist for the provided codes. If unknown codes are specified, the import is canceled.

Common mistakes​

  • The Bill of Materials is not selected automatically — the “Default” flag is not set or the Bill of Materials is archived.
  • The order cannot be saved after selecting a Bill of Materials — the order item does not match the Bill of Materials item.
  • The norms in the order are “not what expected” — check the base quantity of the Bill of Materials (often it is defined not for 1, but for 10/100 units).