Hi Elham
MR21 and CK11n followed by CK24 ar two methods of giving price to a material. Everyone has said this fact in the replies so far.
To add a value to the thread, I would like to say that if you see there are two price fields at costing tab2 in the material master namely 'Planned price' and 'standard price' under 'current' column.
When you do CK11N and CK24 system writes the values at Planned price and at the same time updates the same value to standard price field also. But when you do MR21 system updates standard price fields only. All the material movements happen using value at this field.
This functionality is given to deal with the cases when by mistake some wrong standard cost is updated through CK11n or may be you do not want to cost the material for any reason.
You can not delete price given by MR21 using MR21 for this purpose you have to use MR21 again and make the current price as ZERO.
Now second point, If you don't calculate price by ck11n the cost component split will not be available with the system hence system will not be able to give you different variance categories but simply you will get a 'remaining variance' as a result.
Regards
Rajneesh Saxena