Architecture Decisions and Rationale

The original scope of the Enterprise Architecture Description was focused on an equation with the sum of each of the supporting architecture descriptions being equivalent to the Enterprise Architecture Description. This implied that the scope of the current Enterprise (SoS) Architecture Description Framework was sufficient to provide the glue across all of the other architecture descriptions.

As the enterprise system System Description (SDSF) continued, the number of perspectives and the scope of these perspectives started showing a need to find a way to separate the viewpoints.

The need for a single Enterprise Architecture Description became apparent based upon the following:

• A single place to identify the top level enterprise elements
• To identify the core competencies or organizational capabilities critical to the success of the enterprise.
• Provide a single source for the entire architecture of the enterprise
• To provide a single ownership of the enterprise architecture description
• To establish both an economic system and continuity to ensure a sustainable enterprise is realized.
• Use management models to support the terminology.

As a result, the Enterprise (SoS) System Description (SDSF) was formed by separating the enterprise level elements from those that either define one or more specific technology Architecture Description Framework / descriptions. The Enterprise Architecture Description approach has been updated to reflect this split..

The final reason for the split: The concept of the equation represented the whole is the sum of its parts. Upon further research, the Enterprise is a system of systems that requires a full understanding of the enterprise emergent properties, system element (organization) structure and behavior, and clear roles for the development of this architecture description. In this case, the Enterprise is more than the sum of the individual system elements and needs a well defined definition of the properties, parts and interactions.

The basic elements of the economic system and continuity (e.g. response to events such as security or environmental incidents) needs to be visible at the highest level of the architecture of the enterprise.

A number of management references (Teece, Haeckel, etc) identify dynamic capabilities as a key aspect of the enterprise

Team capabilities are very different from organizational capabilities and an organizational capability model can provide great insight into the structure of the enterprise and key decisions arising from any change.

Organizational Competencies provide a basis for the Economic System and the Continuity Viewpoints.

The Enterprise is an example of Michael Porter's Value System. This Value System actually meets the criteria established by the COMPASS Project for a System of Systems.

The Strategic Plan describes how the whole enterprise works. This strategic plan uses a five case model to bring together all of the elements for the enterprise. This is used as a key input to the planning system. The Enterprise Architecture Description provides the detail needed to complete a strategic plan. Both of these documents are developed together.

The new Enterprise SoS Model provides an opportunity to simplify the System Description (SDSF). This new approach provides a minimum set of elements needed to describe a whole Enterprise. In addition, the concept of Capability Systems allows for any number of extensions to be added as a natural part of the Architecture Description Framework rather than a part of the base model.

Update the Enterprise (SoS) Architecture Description Framework based upon the new ISO 42010:2022 Requirements. This includes:

• Changing the name of the AFD to AVPD

• Changing the name of the Enterprise AF to Enterprise ADF

• Including the Structuring Formalism

• Revising the correspondences.