Architecture is Architecture is Architecture by: John A. Zachman

There appears to be a gross misunderstanding about Architecture, particularly in the information technology community. Many people seem to think that an implementation, an end result, is Architecture. To use an Architecture and Construction example, many people think that the Roman Coliseum is Architecture.

Architecture is Architecture is Architecture by John A. Zachman © 2007, 2011 John A. Zachman, Zachman International, Inc.

Figure 1: The Roman Coliseum

The Roman Coliseum is NOT Architecture. The Roman Coliseum is the RESULT of Architecture. The RESULT of Architecture is an instance of Architecture, an implementation. In the end result, the implementation, you can see an instantiation of the Architect’s Architecture. If an Architect had not created the descriptive representations (the Architecture) of the Roman Coliseum, they could not have built the Roman Coliseum. They couldn’t have even ordered the stones they required in order to build the Coliseum without the Coliseum Architecture, which had to be created long before the Coliseum was constructed.

Architecture is the set of descriptive representations that are required in order to create an object. If you can’t describe it, you can’t create it. Also, if you ever want to change the object you created, Architecture constitutes the baseline for changing the object once it is created, that is, it is the baseline for changing the object IF you retain the descriptive representations used in its creation and IF you ensure that the descriptive representations are always maintained consistent with the instantiation.

If the object you are trying to create is so simple that you can see it in its entirety at a glance and remember how all of its components fit together at excruciating level of detail all at one time, you don’t need Architecture. You can “wing it” and see if it works. It is only when the object you are trying to create is complex to the extent that you can’t see and remember all the details of the implementation at once, and only when you want to accommodate on-going change to the instantiated object, that Architecture is IMPERATIVE. Once again, without Architecture, you are not going to be able to create an object of any complexity and you won’t be able to change it (that is, change it in minimum time, with minimum disruption and minimum cost).

So, the question is, what constitutes the set of descriptive representations relevant for describing an object such that you can create it and change it with minimum time, disruption and cost?

The answer lies in several hundred years of empirical experience learning how to create and change complex industrial products.

There is a universal¹ set of descriptive representations for describing any or all industrial products. It is not mysterious what one dimension of the set of descriptions is as it is derived from the classic six primitive interrogatives that have existed since the origins of language. Answers to the six primitive interrogatives constitute a complete description of anything. Therefore, one set of descriptions includes:

• Bills of Material - What the object is made of.
• Functional Specs - How the object works.
• Drawings - Where the components exist relative to one another.
• Operating Instructions - Who is responsible for operation.
• Timing Diagrams - When do things occur.
• Design Objectives - Why does it work the way it does.

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e.g. the Material Abstraction (WHAT it’s made of)

<li">Airplanes have Bills of Material. <li">Locomotives have Bills of Material. <li">Computers have Bills of Material. <li">All Industrial Products have Bills of Material.

• e.g. the Functionality Abstraction (How it works)
  • Airplanes have Functional Specs.
  • Locomotives have Functional Specs.
  • Computers have Functional Specs.
  • All Industrial Products have Functional Specs.

• e.g. the Geometry Abstraction (Where the components are)
  • Airplanes have drawings.
  • And so on… and so on… and so on.

By the same token, all industrial products have another dimension of descriptive representations. This set of descriptions is deriving from the philosophical concept of “reification”, transforming an idea, something you can think about into reality, a physical thing. This is not a “decomposition”… it is a series of “transformations” as each stage in the series has its own unique manifestation with unique characteristics accommodating different purposes of different participants in the reification process. Here is the other dimension of descriptive representations: