Data Consistency

Businesses rely on their data to make decisions, serve customers, or comply with regulations. Because of this, a key requirement of business applications is that the data is consistent.

In practice, this means that a user sees a consistent view of the data, regardless of how it’s presented. For instance, the user could look at the same data in a summary view, in a grid view, and in a details view.

Furthermore, the data should always maintain its invariants. An invariant is a condition or property that remains true throughout the execution of a program, or within a particular scope. For instance, one invariant could be that the balance of a bank account may never be negative. Another invariant could be that the total of an invoice is always the sum of the individual invoice items.

Data consistency also means that the data should be correct and complete. The same type of data should be entered in the same way; there shouldn’t be any duplicates; and required data should be present.