The data inputting and quality of appraisal data is, at times, weak. For example,
a zip code may be entered as the word 'same' implying the 'same' as the subject
property. But if this data was entered into a database for reporting purposes it
would be considered an invalid zip code. Each vendor has chosen their own data model
to capture the necessary data. Hence, there will be differences between vendors
but most data may be similar. To solve this problem, mappings must be defined so
as to map a field from one vendor into the same field from the other vendor. Our
data model has 50+ tables and 3,800+ fields!