Redoing flats

We are a sheet metal parts fabricator and finisher. We use Tops 300 and Fabriwin and Solidworks.

After having used the Solidworks software for several months, my programmers continue to redo the flats (35% of flats) becuase they find that after bending holes may be out of position or more material is left on one end (or less). These programmers have been programming for at least a couple of years. They swear that they calculate the bend allowance, K factor, etc.

It wasn't much of a problem unitl I started measuring this problem.  Is there a method by which I can find the root cause or at least a systematic method to narrow down the potential causes for this so that we can improve upon this metric. Without having myself to go through the Solidworks tutorial. This problem really caused delays on the production floor and uses up resources.


I would appreciate some guidance on this.

Thanks

EC

SolidworksSheet Metal