Hi Arijit,
Thanks for the wonderfully explained scenario technique :-)
a) Costing Parameters for QM Orders -----> For your plant, check the order type to find out if a costing variant is maintained [PPP2]. Yes - it's there as you are able to create QM order.
***I found that I have PPP3 variant maintained.
c) Account Assignment for QM Orders -----> For the notification type and plant combination, please check what all setup maintained. For example - Order type, Business Area and Account Assignment Details like Cost Center, CO Area, etc.
I believe for your case, it's picking the Cost Center + CO Area which is more related to purchase process, than material's cost center + CO Area. You can try creating an internal CO order and assign this here, relevant to Material and test ,
***I found I have not entered any Internal order or Cost center/CO area.... but I have only entered Business area and Ordertype QN01.
Other thing is in my whole process KP26 is the only place where I am using cost center, to enter the activity/price etc.
Best Regards,