Bills of materials

List what goes into a product, its steps and by-products, and see its cost before you make it.

A bill of materials (BoM) lists what goes into one product, or one batch of it. Costs and stock are worked out from it, and your orders start from it.

Add a BoM

Go to Bills of materials and click New BoM.

1. Choose the Product. For items with variants, you can make one BoM for all variants of an item group.
2. Enter Makes this many: 1, or the size of one batch.

3. Choose the Type:

   • Make this product - you make it.
   • Kit (opens into its parts) - a set of items. Inside another BoM, it opens into its parts. A kit also becomes the item's bundle in Inventory, so invoices and challans made in Inventory take the parts out of stock (this needs Inventory's composite items feature).
   • Subcontract (a job worker makes it) - see Subcontracting and job work.
4. Under Components, click + Add component for each item, with its Quantity.
5. Click Save BoM.

No item yet? You can add it from Items & stock.

Components

• Scrap % adds an allowance for waste.
• Used in step ties the component to one step.
• Tick asks operators to confirm they used it.
• Only for limits a line to some variants.

A component with its own BoM is a sub-assembly. It gets its own order when it runs short, linked to the order that needs it (Standard and above).

Steps

If you use work centres, add Steps: what is done, at which work centre, and the Minutes for the BoM quantity. Add instructions to show the operator.

• Time comes from uses your minutes, or Recent real time: the average of the last so many times this step was done.
• Copy from a BoM adds the steps of another BoM, to change as you need.
• Switch on Steps wait for others to finish to choose what each step Waits for.

By-products

If a process gives you something else as well, add it under By-products with its Share of cost %. It enters stock with that share of the order's cost.

Rules

• If what was used differs from this BoM - warn and let them go on, allow it, or don't allow it.
• An order is ready when - all components are in stock, or only the first step's.
• Default order size, Making takes (days) and Getting ready takes (days).
• Overhead on material % - leave it at 0 to use the one in Settings.

Cost and availability

A saved BoM shows the whole tree on the right: each component, each step, and what is short. Type another Qty to see it for a different amount. Material, Labour, Overhead and Cost each show if your role can see costs.

Other actions:

• Make it - start an order.
• Set item cost - set the item's purchase cost to what the BoM says.
• Copy - start a new BoM from this one.
• Start a change - change it with approvals. See Engineering changes.

If you delete a BoM that orders have used, it is archived instead. It stays on those orders.