https://help.tallysolutions.com/docs/te9rel64/Creating_Masters/Inventory_Info/Bill_of_Materials.htm

Bill of Materials

A Bill of Materials is a list of constituent items along with quantity details that can be allotted for the manufacture of a  certain product, by-product or likewise. This facilitates immediate reduction in stock of the item automatically. This process of listing the items that make up another item is made possible in Tally by enabling the Bill of Materials Facility.

Bill of Material (BoM) is created only for those items that are being assembled in-house. Therefore, you need to specify a BoM at the time of creating a Stock Item or while altering the stock item. For trading items, you do not need a BoM.

To know more, click the links below:

Creating Single Bill of Materials for a Stock Item

Creating Manufacturing Journal for a Stock Item with Single Bill of Materials

Creating Multiple Bill of Materials for a Stock Item

Creating Manufacturing Journal for a Stock Item with Multiple Bill of Materials

Creating Single/Multiple Bill of Material with Type of Item

Creating Manufacturing Journal for a Stock Item with single/Multiple BOM created with Type of Item