1. A computer-implemented method for automatically generating data maps used by applications, the method comprising: receiving information at a computer system identifying a section of data in a data repository having a source object and a target object; receiving information at the computer system specifying a set of map rules, each map rule in the set of map rules configured to match source objects in the data repository to target objects in the data repository in response to a set of criteria; receiving information at the computer system defining literal data as a set of default values to be assigned to fields of the target objects in the data repository where no match is found by the computer system based on the set of map rules between the source objects in the data repository and the target objects in the data repository, each default value in the set of default values comprising predetermined literal data; applying the set of rules to the source object and the target object using the computer system to determine a match between the source target and target object based at least one map rule in the set of map rules, if the computer system determines a match based on the set of rules between the source object and the target object, automatically constructing a first map definition for the section of data in the data repository using the computer system based on the at least one rule thereby assigning the source object to the target object, wherein a field map created from the first map definition assigns data in the data repository associated with the source object to the target object; if the computer system fails to yield a match based on the set of rules between the source object and the target object, automatically constructing a second map definition for the section of data in the data repository using the computer system thereby assigning a default value in the set of default values to the target object, wherein a field map created from the second map definition assigns literal data associated with the default value in the set of default values to the target object; and generating the field map using the computer system based on the first or second map definition.