Dr. Peter Chen is the originator of the Entity-Relationship Model. Entity-Relationship Model is System Analytical Tool that helps to examine a System through Data and design a Structural Database Design.
Today many System Analyze and Design Methodologies are invented from Entity-Relationship Model Concept. ERwin, Designer/2000, Power-Designer, Rational Data Architect are few legendary Computer Aided Software Engineering (CASE) Tool Applications that helps to design and maintain Data Architecture with Bachman, Chen, Crow's Foot and IDEF1X Standard.
Data Architecture can transform into Relational Database SQL Script File through a Computer Aided Software Engineering (CASE) Tool Application. In general, a System Model is graphical method to re-presenting the System Requirement Information between the Stockholder and Technical Team Members.
Business Process Model is a graphical method to re-presenting the collection of Present and Future Business Process or Activity of the Organization to analyze and improve the Current Business Process in the Organization.
Data Architecture is graphical method that helps to re-presenting the Database Structure with Entity, Attribute, Identifier, Constraint and Relationship along with the Business Process Flow of the Organization.