Do you mean you don’t want to RESERVE or you don’t want to REVERSE the Item Ledger Entries?
If you don’t want it to reserve you item ledger entries, then you need to change the Reserve Option on the Item Card to Optional, then you can change the reserve option on the Credit Memo to not reserve the item ledger Entries.
If you don’t want it to REVERSE the item ledger entries, then you need to post the credit memo without the item on the credit memo. If it’s only the VAT you need to adjust, then you can create a G/L line with the type VAT Only. But the best way is that you create a cedit memo for the full amount, and the a new credit memo with the correct registration. The problem of course is that you have already consumed the 6 for your production, so it will not be 100% correct, even if you do this.
If you don’t want it to REVERSE the item ledger entries, then you need to post the credit memo without the item on the credit memo. If it’s only the VAT you need to adjust, then you can create a G/L line with the type VAT Only.
But the best way is that you create a cedit memo for the full amount, and the a new credit memo with the correct registration. The problem of course is that you have already consumed the 6 for your production, so it will not be 100% correct, even if you do this.
"but it should adjust the purchase account, vendor account, vat account. "
If you mean by that you want to affect the cost of the item too (because purchase account is reduced)
I suggest to create a credit memo having as line “charge item” that posts to the same purchase account of the posted item entry and assign it to the line containing 10 pcs, that will reduce the purchase price in the item ledger entry and the cost amount actual.
if the vat amount that you want to reduce is the value calculated on this line amount, then u can use the same vat product posting group as the invoice and the system will calculate the same VAT value and deduct it.