DW is a collection of decision support technologies, aimed at enabling knowledge worker to make better and
faster decision [5]. It is the heart of Business Intelligence (BI) System and contains all the information integrated
from heterogeneous source into multidimensional schema to enhance data access for analysis and decision making.
Data from various sources go through tremendous Extract, Transform and Loading (ETL) process that clean,
transform and modify data so that could match multidimensional schema in DW. High volume of data from multiple
sources causes high probabilities of errors and anomalies. Therefore, data needs to be transformed, scrubbed and
audited before they are loaded into DWs.