Refer the link for understanding the concept of Intelligent Search for Material and Vendor in Purchase Order Creation Screen in SAP.

Intelligent-Search-of-Vendor-and-Material.docx

Issue

How to activate the Order Type name along with description in SAP Transactions?

If you want to change the several materials old material group to new material group then follow the following steps :- 

Step 1. Find all the materials with old material group either from MM60 or SE16(MARA table)