As a business analyst or a team member on an IT project it is necessary for you to access this data dictionary.
For example say for a University Management System for some university Enrollment number can be of this format 2019005013. If you go through the data dictionary you will get to understand that
1)Digits for the enrollment number are 10, first four digits is the year of enrollment, next two digits are the branch, next three digits is the running number.
2)Here it may also be provided that, next 3 digits 001 corresponds to say Computer Science and Engineering branch , 002 corresponds to Electronics and telecommunication and so forth
3)The last 3 digits are the running enrollment number of the individual
So wherever for this database enrollment numbers will utilized in which ever tables in the database the same format will be utilized.
For reasons of interoperability and uniformity the some very key data elements of your database may follow the same definition across industry. So it is not unusual for multiple Insurance companies follow same format or pattern for a policy number in their insurance database systems. Sometimes this is mandated by the regulator at other times industry consortium's come up with a common data dictionary for all the companies. For example ACCORD is one such standard for data interchange and exchange in Insurance industry. Quoting Wikipedia : “ACORD, the Association for Cooperative Operations Research and Development, is a non-profit organization that provides the global insurance industry with data standards and implementation solutions. ACORD is widely known across the industry for the publication and maintenance of an extensive archive of standardized forms. ACORD has also developed a comprehensive library of electronic data standards with more than 1200 standardized transaction types to support exchange of insurance data between trading partners.”
So as a Business Analyst you are suggested to go through and internalize the data dictionary for your solution. If such a data dictionary is not available it is recommended such data dictionary may be prepared. Since finalization of structure and relationship of data elements is primarily the responsibility of data base designer the role of a Business Analyst is at best restricted to documenting the same. The Business Analyst should also be aware of any data dictionary related standards for his industry
Benefits of Preparing and Utilizing a Data dictionary
1)Consistent data definitions leading to uniformity and quick s/w development
2)Quick understanding of data elements and business logic.