Practice Note: Building on Established Reference Models

The term reference model is already well established within systems engineering, enterprise architecture and other engineering disciplines. It generally refers to an abstract representation of a domain that defines concepts, their relationships and a common frame of reference while remaining independent of a particular implementation.

For readers unfamiliar with the concept, the Wikipedia article provides a concise overview of the commonly accepted definition:

https://en.wikipedia.org/wiki/Reference_model

This Practice Note does not attempt to redefine what a reference model is. Instead, it establishes the perspective adopted throughout this body of knowledge.

Many reference models successfully describe what exists. They identify concepts, components and relationships. They provide a shared vocabulary and a structural understanding of a domain.

In practice, however, organizations face a different challenge. Over time, the structure often survives while the understanding behind it gradually disappears. Documentation remains available, yet the reasoning that shaped it becomes difficult to reconstruct. New team members can read the model without fully understanding why it exists, what assumptions influenced it or under which circumstances it should evolve.

From the perspective of these Practice Notes, a reference model is therefore valuable not only because it represents a domain, but because it enables the continuity of understanding of that domain.

Three questions become particularly important.

• Does the model preserve the intent behind its concepts and relationships?
• Can its meaning be reconstructed when context has been lost?
• Can the model evolve without losing the reasoning that originally made it useful?

These questions extend beyond documentation. They concern the preservation of organizational knowledge and the ability to make informed decisions as organizations, products and capabilities evolve.

The Practice Notes therefore build upon the established concept of a reference model rather than replacing it. Their contribution is to explore how reference models can support continuity of understanding, deliberate development and defensible assessment throughout the lifecycle of organizations, capabilities and products.

Future reference documents in this body of knowledge adopt this perspective as their foundation.