Use Cases: When to use an ERD vs Data Model?

Entity Relationship Diagrams (ERDs) and detailed data models are two important tools employed by Salesforce architects to design and manage data. An ERD is a graphical representation of the relationships between conceptual “entities”, while a detailed data model provides description of the physical objects, the relationships between them, and the attributes of the objects.

ERDs are great as starting point and are usually meant to represent the data without assuming how the data will be stored. Think of ERDs as solution-agnostic: you don’t yet know if the data will be captured as separate objects, record types or fields in the database. When drawing an ERD, you are trying to uncover relationships, overlapping or redundant data, and group entities into logical structures.

A detailed data model, on the other hand, is used to provide detailed information about the physical objects, the relationships between them, and the attributes of the objects. A data model is meant to capture the physical structure of a database. Detailed data models also require you to think how the data will actually be stored in the database. For example, a detailed data model for the Customer object may include the object’s attributes, such as name, address, and phone number, as well as the object’s relationships to other objects, such as the Account object or the Order object.

In summary, ERDs are best used as the starting point for new capabilities to discover the relationships and understand the data relationships without prescribing how data will be stored.

A detailed data model is the recommended method when you are trying to understand the current, actual database configuration or you want to design how the database should be structured.