One of the great impediments to effective communication is that the same word, phrase, or concept can mean different things to different people. Conversely, different people have different terms for the same idea.
The day-to-day operations of a business require a common understanding of terminology. Employees and management who come to the company from different industries might understand terms differently, and in companies that are built by merger and acquisition, there can be subtle (or not-so-subtle) differences in both terms for the same idea and meanings for the same term.
Take “customer,” for example. What constitutes a customer? Is it someone who set up a user account on your e-commerce site, but hasn’t necessarily made a purchase? Someone who has asked for a quote? Placed an order? Paid an invoice? Each of these could be a “customer.”
Where it really gets fun is when you try to put together a report that deals with customers and you’re pulling data from different systems—each of which might have a different notion of what constitutes a “customer.” You won’t get reliable results if you simply cobble together data from every table labeled “Customers.”
Why you need a business glossary
Hence the need for a business glossary. A business glossary establishes a shared understanding of terms across the organization. Using the business glossary, BI professionals can examine the metadata from the company’s various data assets and determine, for example, what “customer” information represents actual customers, as defined in the business glossary.
How do you build a business glossary?
A good place to start is the company’s data assets, particularly metadata from reporting tools, because a company’s reports will usually contain the information that is most important to that company. Tracing a report’s metadata back to the original sources can indicate what is meant by each term in that report. This is useful for identifying when a term means different things in different reports, as well as when data sources used in a single report don’t share the same understanding of a term.
Business Glossary vs Data Dictionary
A business glossary is not the same thing as a data dictionary. A business glossary defines business terms for human understanding, whereas a data dictionary is a collection of metadata about data objects, assembled for system understanding.