In Six Sigma machining operations, fighting variation is a never-ending quest. Just when production engineers and quality control specialists think that they have vanquished the variation dragon, the monster can reappear because of changing production requirements or other marketplace factors.

Now, however, with the help of a new breed of flexible rotary transfer machines that offer many of the benefits of multistation machining without some of the typical drawbacks, some shops are fighting back more effectively against variation. And while the variation beast can never be killed entirely, it is rearing its ugly head less often--in some shops, at least.