Document data quality requirements and define rules for measuring quality. In most cases, data quality levels are related to the "fitness" of information for the purposes of business users. Begin by collecting requirements: Engage business users, gain an understanding of their business objectives and solicit their expectations for data usability. That information, combined with shared experiences about the business impact of data quality issues, can be translated into rules for measuring key dimensions of quality, such as consistency of data value formats in different systems, data completeness, currency and freshness and consistency with defined sources of record. As part of the process, create a central system for documenting the requirements and associated rules to support the development of data validation mechanisms.