1. A method for validating data transformed from a source repository to a target repository, the method comprising: receiving, by a data validation computing device, a data transformation specification from a user; analyzing, by the data validation computing device, the data transformation specification to determine data transformation rules, wherein the data transformation rules are indicative of a relationship between corresponding fields of the source repository and the target repository; generating, by the data validation computing device, test cases and test scripts based on the data transformation rules; determining, by the data validation computing device, a number of records on which the test cases and the test scripts are to be executed; executing, by the data validation computing device, the test cases and the test scripts in an order based on the data transformation rules, on the source repository and the target repository to validate the relationship between the corresponding fields of the source repository and the target repository, wherein execution of the test cases and the test scripts is initiated serially when the determined number of records is less than a critical threshold, and wherein the execution of the test cases and the test scripts is initiated in parallel when the determined number of records is more than a critical threshold; and generating, by the data validation computing device, a log file indicative of the outcome of the execution of the test cases and the test scripts.