Chapter 4. Conceptual Information Modeling

Making a conceptual information model allows identifying and describing the relevant concepts of a business domain, including entity types and associations between entity types, as well as integrity constraints and business rules. A conceptual information model does not describe (the elements of) an IS. Rather, it describes (elements of) a real-world domain. The primary audience of a conceptual model are not IT experts, but subject matter experts for the business domain under investigation, such as marketing or controlling experts. The main purpose of a conceptual model is to serve as a basis in the communication between IT experts and business experts.

Conceptual information models can be expressed textually (e.g., in the form of a list of entity types, each described with a list of attributes) or visually, in the form of diagrams created with a diagram language, such as Entity Relationship Diagrams (ERDs) or UML Class Diagrams. ERDs have been mainly used for designing Relational Databases, while Class Diagrams are being used both for designing the Java/C#/etc. classes of an app written in Java/C#/etc. and for designing the corresponding tables of the Relational Database underlying the app.

There are several tools that allow creating both Class Diagrams and ERDs. For instance, StarUML ( and Visual Paradigm ( are desktop tools that support both UML and ERDs. Visual Paradigm has a free trial version that can be used, however, for 30 days only, while StarUML has a free evaluation version without a time limit.

GenMyModel ( is an online modeling tool that supports UML Class Diagrams (and other diagram types) and has free plan.