[fsa]

sir you are right..but my concern is flatness 0.5mm on both faces and parallelism 0.02 with respect to Datum A..they both are conflicting each other ..if i maintain flatness 0.1mm on one face and 0.2mm on other face,,then the parallelism 0.02mm is automatically out of range..am i right ???

[Ramseis]

The datum face for the parallelism is the opposite face of the part. Therefore the smaller parallel tolerance could be maintained if the part faces were out-of-flat in the same direction. Sort of as if the part was a bent sheet.