JammedStab's method should work: i.e. a comparison between planned/expected data and actual data. Further, I think there needs to be a whole attitude change. Many of us were brought up in the era of 'gross error checks'. There were little tricks we all used to have a 'ball-park figure' in our heads. This covered many items. Today's education, in so many fields, is to use japanese brains and believe what they tell you; no gross error check in your own brain. This has been contributed to by the lack of mental arithmetic in schools I often get cadets on the TQ course who struggle with basic speed/distance/time calculations. Ground speed/ROD/VS calculations. It's all VNAV and FMC to find the answers. Guys who use calculators to add up load sheets etc. Often it's slower anyway, but they have not been schooled in this way and given the tools.