I can tell you a horror story. At the beginning of the reporting system, we received a fine from the government because of an incorrect tax calculation. When I started to investigate this thing, I figured out, that due to inconsistency of materials control at both of our warehouses, some of them were not included in the total list. Long story short, the finance department thought we had already used them and calculated the tax difference that cost us the government sanctions. I was really mad that all calculations were made almost on paper and found a solution here after which we implemented an athematic monitoring system for this hiccup to never happen again!