A Business System is a logically grouped set of related components. They may be deployed in total or piecemeal depending on the capabilties provided by its components and the capabilities required by the enterprise. A Business System may be composed of Business Apps and their Application Components, local DB Schemas, and Services.

Each Business System has its own package with subpackages for each of its components. The components' location in the Project Browser is not important, but the Business Apps are usually located under the Business System. On the other hand, you may decide to keep the Services in a separate package under the Service Architecture and the DB schema(s) under the Data Architecture.

The following diagram shows the Program Management Business System with its Business Apps and a local DB Schema (which resides in the Data Architecture View). 

Each of the System Components is linked to the Business System with a nesting relationship. The Player Rating Front End Business App and Program Development DB Schema have been pulled out of the Business System's icon to show this. (Nesting connectors disappear when placing the nested element over the parent). This relationship is used by the (EA)² SQL views to determine a Business System's components without regard to their location in the Project Browser.

Depending on the level of detail you desire, Business Apps can be treated as black boxes (often used by organizations that mainly purchase and integrate applications) or as a set of Application Compoenents (used by those who develop their applications. The two approaches can be used together, with the black box approach providing high level context and the component approach providing the details. An example of the latter is shown below.