Enterprise Foundations

Your Platform to a Successful Enterprise Architecture Capability

Modelling the Enterprise

The "right way" to the model is a subject of endless debate among enterprise architects.  This debate is often ill conceived and does nothing to add value to the enterprise.  The fact is, there is no right way to model.   A model serves a purpose.  The question isn't "is this model right or wrong?" but "what is the intended purpose of the model and does it achieve that purpose?"

In general, models serve three broad purposes in enterprise architecture:

• They are used to express requirements;
• They are used to analyze the enterprise; and
• They are used to specify solutions.

When models are used to express requirements, it is critical that the meaning of the model is understood by both the architect and the source of the requirement.  Equally important is the model must support communication of requirements and their impact across the various business disciplines.

When used to analyze the enterprise, the primary concerns are validity of the analysis and trust in the analysis.  Models used to analyze the enterprise are typically more technical in nature and require expertise to create and interpret.  Care must be taken within the architecture practice to ensure that modellers have the necessary skills to ensure the results from the modelling activity are valid.  Care must also be taken to ensure that decision makers trust the results.  In this regard, the debate over the "right way" to model has some merit.  It is important to be consistent.  So while there is no universally correct way to model something, there is the established modelling practice and that should take precedent.

When models are used to specify solutions, the primary concerns are correctness, the absence of ambiguity,  and absence of design bias.  Correctness means that a solution that meets the specification will result in the expected solution.  Absence of ambiguity is self evident; there should be no confusion over what the specification means. Absence of design bias means that models used for specification should be declarative.  They should clearly express what is needed and not how it should be implemented.

There is another purpose for enterprise architecture models.  Enterprise architecture models are used to communicate the design of the enterprise.  This communication occurs across the enterprise at any point in time and over generations.  The models provide the conceptual schema for the enterprise.  It is this use that creates the most significant debate as the various cultures and subcultures within the enterprise clash over language.