Dear Mayuresh
If you use Production versions as suggested by Rupesh Sir,You will get Variance in all the production orders for which you use the version which is not considered for Standard Cost Estimate (SCE).
SCE is done (CK40N) either by using First Production version or by using production version defaulted in the material master itself. Or if SCE by CK11N you give a production version for the purpose. But in any case it will use only one production version for SCE purpose.
So whenever you will use other version you will get variance in the order.
Regards
RS