1. A machine-implemented method, comprising the steps of: storing identification data that defines consistency rules that were specified by one or more users for identifying inconsistencies between a plurality of data sources that includes a first repository of data and a second repository of data; wherein the consistency rules include at least: a first consistency rule that specifies (1) a first location of a first set of values in the first repository of data and a second location of a second set of values in the second repository of data; and (2) a first relationship between the first set of values and the second set of values; a second consistency rule that specifies (1) a third location of a third set of values in the first repository of data and a fourth location of a fourth set of values in the second repository of data; and (2) a second relationship, different from the first relationship, between the third set of values and the fourth set of values; executing, in a first phase, a first sequence of instructions that cause one or more processors to perform the steps of: (a) reading, from a file separate from the first sequence of instructions, said identification data; (b) while the first sequence of instructions is executing, dynamically determining the consistency rules based on the identification data read from the file separate from the first sequence of instructions; (c) evaluating the consistency rules against the plurality of data sources by comparing values in the first repository of data to related values in the second repository of data based on the consistency rules; (d) during the evaluation of the consistency rules, determining at least one inconsistency between the values in the first repository of data and the related values in the second repository of data, based at least on one of the first relationship or the second relationship, as specified in said consistency rules; and (e) based on the evaluation of the consistency rules, generating output data that identifies the at least one inconsistency; storing resolution data, different from the identification data, that defines resolution rules that were specified by the one or more users for resolving one or more inconsistencies between the plurality of data sources; wherein the resolution rules include at least a particular resolution rule that specifies a specific manner in which to resolve a particular inconsistency between the first repository of data and the second repository of data by modifying data in at least one of the first repository of data and the second repository of data; and executing, in a second phase, subsequent to the first phase, a second sequence of instructions that cause performance of the steps of: (f) accessing the output data; (g) identifying the at least one inconsistency based on the accessed output data; (h) reading, from a file separate from the second sequence of instructions, said resolution data; (i) while the second sequence of instructions is executing, dynamically determining the resolution rules based on the resolution data read from the file separate from the second sequence of instructions; and (j) based on the determined resolution rules, modifying data in at least one of the first repository of data and the second repository of data in the specific manner indicated by the particular resolution rule to resolve the at least one inconsistency.