In PP,Attach The Components Drawing In a BOM

What are the procedure to attach the components drawing in a BOM?

1) Attaching document as an item in the item overview:
…go to the `General Item Overview' screen
…select the tab page `Document'
…enter item category `D'
…dropdown and select the document you want to attach
…the system automatically selects the respective document type, document part, document version and document description

2) Attaching document to an item:
…go to the `General Item Overview' screen
…select the particular item by F2
…the item all data screen appears
…go to tab page `document assignment'
…dropdown and select the `document type' you want to attach …dropdown and select the document you want to attach
…the system automatically selects the respective document part, document version and document description

3) Attach document to the header material:
…go to header overview screen
…go to tab page `document assignment'
…dropdown and select the `document type' you want to attach
…the system automatically selects the respective, document part, document version and document description
(Transaction CV01N for document creation)