The PERA Generic Enterprise Model is comprised of three basic components:
These are depicted as three "columns" which begin with Enterprise Definition and end with Enterprise Dissolution (see diagram below at left).
In fact however, each of the three components has an interface with the other two, so the PERA diagram might actually be better represented if it were "wrapped around" into a sphere. Unfortunately, this is difficult to represent on a two dimensional page.
PERA indicates that the next most basic way to structure the enterprise model is by "phase" as indicated by this diagram. During each phase of the enterprise, different diagrams are used to reflect the developing detail as the enterprise moves from initial Definition to Operations Phase, to Dissolution.
Taken together, the above defines the complete Enterprise Model Although formats for documenting of each of the three model components (Facilities, People and Information Systems) vary, the intent is the same: to provide a coherent and coordinated representation of the enterprise during that phase. It is also true for all three model components, that additional detail is added in each sucessive phase by building on the information defined in the previous phase.
The following diagram shows typical "deliverables" or documents produced at each phase of the Enterprise. These documents define the architecture of each of the enterprise components during that phase, i.e. the manufacturing facilities component, the Human and Organizational component, and the Control and Information Systems component.
Since PERA represents the full life cycle of the Enterprise, all existing Enterprise documents and tools can be fit within its structure. As the Enterprise is developed, and increasing levels of detail are defined, it is possible to see how each of the contributing groups and their "deliverables" are related to the others.
Since PERA is a GERAM, and can be used to represent any enterprise. Similar deliverables, tools, products, etc. which are used in different industries can be related, and perhaps also rationalized.
For more discussion of the concept of Enterprise Architectures see "What is an Enterprise Architecture" the Frequently Asked Questions section.