There are common-sense reasons such as enhanced understanding, productivity, predictability, repeatability, consistency etc. for the use of models, templates, standards, patterns...
But why do we use frameworks, reference or generic architectures or, for that matter, why do we employ architecture? What is an Architecture method?
There is a clear distinction, often not made, between the value of architecture, the value of generic and reference architectures and that of an architecture framework. That is because we have to distinguish in the first place between an architecture, a reference and generic architecture and an architecture framework.
An Architecture describes a system in terms of its components and interconnections that channel the system flows. Architecture often covers the physical resources that realise the system. Any system has an architecture or structure but some structures are simpler to control, maintain and change than others. The enterprise is a system.
The value of architecture itself resides in the structured description of the system which enables its faster comprehension, analysis, management, change and transformation.
Architecture principles guide the system transformation.
Generic Architecture To represent a whole class of systems, an architecture must be "generic" enough.
TM Forum's Frameworx is primarily a generic architecture because it describes the entities of a digital media company, i.e. the business processes, information and application maps.
Here is a sample one-page generic architecture describing the key functions and flows of an enterprise.
A generic architecture enables a template-like approach to system modelling. Its value resides in the fact that it cuts down the modelling effort, renders it predictable, it employs the vast experience of others. TOGAF Continuum emphasises the value of generic architectures.
Reference Architecture is a generic architecture adopted as a standard for the analysis and design of systems in the same class. To be validated as a reference, rather than declared as such by its promoters, an architecture must be generic and adopted enough, having been reused in many endeavours.
A reference architecture facilitates reuse, predictable and comparable designs, reproducibility and as such productivity which saves time and costs. A reference architecture exhibits all the benefits of standards.
TOGAF is a reference architecture not so much because it is used as a reference model by the industry but because it is specified by a standards organization with industry participation.
Architecture Framework is the architecture of an architecture. It looks like the skeleton of a body, the contents page of a book or the chassis of a car. It enables us to plug into the framework complying with architecture artefacts to build the Architecture.
It enables us to break down the system complexity into independently manageable parts. It facilitates as such independent and parallel change and as a result, quick and without side effects.
The architecture framework describes the key components of the/any Architecture and its relationships. It enables architecture navigation. A Framework is usually described in terms that stakeholders can grasp. A Metamodel is a technical expression of a framework. It is illustrated as a class diagram illustrating the architecture organisation. It is ultimately employed as the repository schema for the architecture tool.
An Architecture Method should exhibit:
- A generic/reference architecture for a class of systems
- An Architecture Framework and Metamodel that describe the structure of the architecture and enables its navigation
- An ensemble of Architecture Principles that guide the transformation of a system to reduce its complexity and facilitate change
- A system modelling process and associated controls to ensure proper governance, the application of principles, and tools to measure progress, maturity... This process is part of an overall system transformation process that describes best practices, requirements, risks...
- A strategy framework that enables the specification and the incorporation of strategic directions into the modelling and transformation
An EA tool, that incorporates a reference architecture, framework and method, streamlines the architecture development process by supplying the various diagramming tools, architecture templates, modelling repository structured by your metamodel, strategy specification, mapping, planning and process management tools and enables architecture visualisation and navigation.