1. How often are errors made?
The lower the error rate the better the process. Errors mean double handling requiring more resource and higher cost.
A good error rate for human data entry is <2%. A really good data entry person could achieve <1%, while a well programmed computer data capture solution could achieve <0.25% (there would be human quality audits as part of this).
How do you determine your error rate? Check a sample, not everything, a sample is sufficient – say 5% of the volume or even just 100 transactions. If this is to hard can you identify corrections, rework or the number of transactions reversed? It may not always be caused by an error but it is an easy way to estimate the error rate.