Work order variances come in a number of forms - material, labor, method, std cost. We have found it helpful to use a few simple browses that you can put together yourself. A browse on wo_mstr/wod_det will tell you if you if you have under or over issued materials and let you sort by material variance as a dollar or percent amount using calculated fields. This can help find those items that were not issued prior to accounting close.
For labor variances, play with a browse on wo_mstr and wr_route. You can create a calculated field for efficiency % and sort by that to find outliers.