Bill of Materials (BOM)

You’ll find this under Manufacturing → Bill of Material.

A bill of materials (BOM) lists what is needed to make an item. It includes the output quantity, materials, operation sequence, and any scrap or by-products. ERPX copies this information to the work order when a production run is created.

A BOM produces a stated quantity, not necessarily one unit. A BOM whose quantity is 100 describes a batch of 100 units, so every material line is the amount required for that full batch. Keep this in mind when calculating per-unit material requirements and costs.

Two kinds of BOM

Kind	Written against	Use when
Ordinary BOM	One concrete item	The item has no variants, or one variant requires a different recipe
Template (Super) BOM	A template item that has variants	One recipe should cover every colour, size, or grade of an item

This page covers an ordinary BOM. Operations, warehouses, costing, scrap, and versioning work the same way for both types. A template BOM also has material rules that ERPX applies to the selected variant when a work order is created.

If you produce many variants of one item, read Template (Super) BOM before creating a separate, nearly identical recipe for every variant.

What a BOM is made of

Section	Holds
Materials	Components and sub-assemblies consumed
Operations	The steps performed, in sequence, with standard times
Scrap Items	Waste with a recoverable value
By-products	Saleable secondary output

The total cost uses all four sections:


Raw Material Cost  +  Operating Cost  −  Scrap Value  −  By-product Value  =  Total Cost

Creating a BOM

Open the screen

Go to Manufacturing → Bill of Material and click New.

Choose the item and batch quantity

The item is the finished good. Quantity is what one run of this BOM produces. Leave it at 1 unless your production and costing use batch quantities.

Set the warehouses

Source, WIP, Finished Goods, and Scrap set here become the defaults on every work order created from this BOM. Set them here if the same warehouses are normally used. They can still be checked on each work order.

Add materials

Each line is an item, a quantity, and a unit. A line whose item has its own BOM becomes a sub-assembly. See Sub-assemblies.

Add operations

Sequence them in the order the work happens. Each carries a workstation type and a standard time, and together they produce the operating cost.

Add scrap and by-products

These sections are optional. Add them when they apply so their value is deducted from the production cost.

Save, then Submit

Draft BOMs cannot be used by a work order. Submit makes the BOM usable and locks it.

Header fields

Field	What it means
Name	Identifier for this BOM
Item	The finished good produced
Quantity	How much one run of this BOM makes
UOM	Unit the quantity is stated in
Rate Of Materials Based On	The valuation method used to cost materials. The default is Valuation Rate
Currency	Currency the costs are held in
Is Active	Whether the BOM may be used at all
Is Default	The BOM offered first for this item
Is Active Version	Only one version per item can hold this
Template (Super) BOM	Marks this BOM as a rule-based template covering every variant of the item. See Template (Super) BOM
With Operations	Whether the BOM includes operations and their operating cost
Transfer Material Against	Whether material is transferred against the work order or against operations
Allow Alternative Item	Permits substitution when material is transferred
Tolerance Percentage	Default tolerance inherited by work orders created from this BOM
Status	Draft, Submitted, or Cancelled

Cost fields

Field	How it is derived
Raw Material Cost	Sum of material lines at the chosen rate basis
Operating Cost	Sum of operation costs
Scrap Value	Recoverable value of scrap lines
By-product Value	Value of secondary output
Total Cost	Materials + operating − scrap − by-products

Material lines

Field	What it means
Item	The component
Qty / UOM / Conversion Factor	Quantity per BOM run, in the buying or issuing unit
Stock Qty	The same quantity in the item’s stock unit
Rate / Amount	Valuation of the line
Is BOM / Child BOM	Marks the line as a sub-assembly and points at its recipe
Source Warehouse	Per-line override of the BOM source warehouse
Fixed Consumption	Quantity does not scale with the run size
Resolution Mode / Qty Mode / Conditions	Template BOMs only. See the three rule types

Fixed Consumption is for things a run needs once regardless of size: a setup sheet, a machine purge, a test piece. Leave it off for anything that scales, or a run of 500 will requisition the same material as a run of 5.

Sub-assemblies

A material line whose item has its own BOM is a level boundary. It is not flattened into its own components on the parent.

Exploding a BOM into a work order requirement

Multiplying the recipe by the run quantity is the easy half. The half that catches people out is Fabric Panel: because it carries its own BOM it is a level boundary, not a line to requisition. Tick Use Multi-Level BOM and ERPX raises a child work order to make it; leave it off and you must have it already in stock.

On the work order	Behaviour
Use Multi-Level BOM off	The sub-assembly is requisitioned like any other material and must already be in stock
Use Multi-Level BOM on	ERPX creates a child work order to make it, and the parent waits for the child’s output

ERPX refuses a BOM containing a circular reference, meaning an item whose BOM eventually contains itself. The explosion stops and reports the cycle rather than looping. If you hit this, one of the nested BOMs is pointing back up the tree.

Operations

Field	What it means
Sequence ID	The order work happens in. Job cards inherit and enforce it
Operation	The step, from the Operation master
Workstation Type	What the estimate is costed against
Time In Secs	The stored standard time. Minutes are derived from it
Time Unit	Whether the form shows minutes or seconds
Batch Size	Units produced per cycle of this operation
Hour Rate	Copied from the workstation type
Operating Cost	Time × hour rate, scaled per the cost mode
Fixed Cycle	Cost is charged per cycle rather than per unit

Operations use a Workstation Type for planned cost, so ERPX can estimate the run before a specific machine is assigned. The job card records the actual workstation used, allowing reports to compare planned and actual costs.

Versioning

Use a new BOM version when the production recipe changes. This keeps the BOM used by older work orders available for reference.

Field	What it means
Version	Version number in the chain
Is Active Version	Only one version per item holds this at a time
Original BOM	Points at the first BOM in the chain

A work order keeps the BOM details that were copied when it was created. Publishing a new version does not update work that is already in progress. For example, a recipe change made in March will not alter the production cost of a January work order.

Supporting masters

If these records are new to you, the standalone Shop-floor Setup guide walks through the order to create them and explains how their rates and times reach production.

Workstation Type

Open Manufacturing → Workstation Type.

This record provides the standard cost model. Four component rates combine into one hourly rate:

Field	What it means
Hour Rate Electricity	Power cost per hour
Hour Rate Labour	Standard labour cost per hour
Hour Rate Consumable	Consumables burned per hour
Hour Rate Rent	Floor space and depreciation per hour
Hour Rate	The sum. Calculated, not typed
Daily Operating Hours	Capacity per day, used by capacity planning

Workstation

Open Manufacturing → Workstation.

The actual machine or bench. Job cards record against a workstation, which is what turns an estimate into a measured cost.

Field	What it means
Workstation Name	e.g. Cutting Table 2, Press A
Workstation Type	Where the default rates come from
Production Capacity	Hours available per day
Daily Operating Hours	Available hours for this particular machine

Operation

Open Manufacturing → Operation.

The library of steps (Cutting, Stitching, Pressing, QC) with their default workstation type and standard time. Defining them once here keeps two BOMs from disagreeing about what “Finishing” means.

Routing

Open Manufacturing → Routing.

A saved, ordered sequence of operations that can be pulled into any BOM instead of rebuilding the same operation list by hand. Operations are drag-ordered, and a routing must be approved before it can be used.

Tools

Tool	Go to	What it does
BOM Hierarchy	Manufacturing → Bill of Material	Shows the full BOM tree by level, with combined material quantities
BOM Detail	Manufacturing → BOM Detail	The single-BOM form view
Resolution preview	BOM builder, template BOMs	Shows the actual material list generated for a selected variant
Check all variants	BOM builder, template BOMs	Tests every enabled variant and reports an OK, warning, or error result
Missing Rates	Manufacturing → Bill of Material → Missing Rates	Every component with no valuation, which is usually why a BOM cost looks too low
BOM Stock Report	Manufacturing → Reports	Component availability for a proposed run, with UOM conversion
BOM Operation Report	Manufacturing → Reports	Compares time and cost by operation across BOMs to help identify bottlenecks

Check Missing Rates before you trust any BOM cost. A component with no valuation contributes zero, so the BOM understates the product cost instead of reporting an error.

Subcontracting BOMs

A BOM created through Subcontracting BOM is flagged Is Subcontracting BOM and is read-only in the BOM form. Edit it from the subcontracting screen instead. See Subcontracting.

Common validations and troubleshooting

Message / behaviour	Why	Fix
BOM not offered on a work order	It is Draft, inactive, or not the active version	Submit it, or mark it active
Circular dependency reported on explosion	A nested BOM points back up its own tree	Break the loop in the child BOM
BOM total cost looks far too low	Components have no valuation rate	Run Missing Rates
Operating cost is zero	With Operations is off, or the workstation type has no hour rate	Set the rates on the workstation type
Material quantity did not scale with the run	The line is marked Fixed Consumption	Clear the flag if it should scale
BOM form is read-only	It is a subcontracting BOM	Edit it under Subcontracting → Subcontracting BOM

Tips

Keep the BOM quantity at 1 unless you plan and cost in batches. A quantity of 1 makes per-unit material and cost calculations easier to understand.
Set the four warehouses on the BOM rather than on each work order. They are defaults that inherit downward.
Build routings for operation sequences you use repeatedly. You can then update and reuse the sequence instead of entering it on every BOM.
Record scrap and by-products even when the value is small. They are subtracted from product cost, so leaving them out overstates every margin downstream.
Create a new version for a genuine recipe change. Use a normal edit only for a correction that does not change production requirements.

Core Concepts: explosion, levels, and costing
Shop-floor Setup: workstation types, machines, operations, and routings
Production Plan: rolling BOM demand into a plan
Work Orders: using a BOM to produce
Job Cards: working the operations
Subcontracting: outsourced operations