TOGAF 9: difference between enterprise continuum and architecture repository

Question

I am trying to understand the core concepts of TOGAF 9.

No matter how often I read the explanation in the TOGAF manual, I don't understand the differences and the relationship between the Enterprise Continuum and the Architecture Repository.

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Some quotes from the documentation:

Enterprise Continuum

"The simplest way of thinking of the Enterprise Continuum is as a view of the repository of all the architecture assets. It can contain architecture descriptions, models, building blocks, patterns, viewpoints, and other artifacts"

"The Enterprise Continuum provides a valuable context for understanding architectural models: it shows building blocks and their relationships to each other, and the constraints and requirements on a cycle of architecture development." (pages 565 and 48)

Architecture Repository

"This section of TOGAF provides a structural framework for an Architecture Repository that allows an enterprise to distinguish between different types of architectural assets that exist at different levels of abstraction in the organization." (page 593)

Assumptions

The samples/template-package of TOGAF contains a word document "TOGAF 9 Template - Architecture Repository.doc", so

1) I think of the architecture repository as a large document, containing all outputs of all projects related to the architecture.

2) The enterprise continuum is another document classifying the contents of the architecture repository from foundation architecture to organization architecture and providing information about the relationship between these objects.

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What is the difference/relationship between the enterprise continuum and the architecture repository?

Answer 1

The architecture repository is the content - all your designs, policies, frameworks etc.

The continuum is the means by which you classify them. It's not just where something is in terms of foundation->organisation. It covers everything, so as per above you will have classifications of 3rd party frameworks, business principles, Technical Standards, all those things too that are present in your enterprise.

Within the EC exists the Architecture Continuum and the Solutions Continuum. THis is where you classify your ABB's and SBB's according to the Foundation, CSA, Industry, and Organisation tiers.

Answer 2

From Open Group / Core concepts (http://pubs.opengroup.org/architecture/togaf9-doc/arch/chap02.html#tag_02_06): The Enterprise Continuum is a view of the Architecture Repository (emphasis added). Whereas the repository is the store of artifacts, organised in a specific manner.

Answer 3

Enterprise Continuum = Architecture Continuum + Solution Continuum

What is Continuum

Continuum models explain variation as involving a gradual quantitative transition without abrupt changes or discontinuities

The Enterprise Continuum provides a consistent language to communicate the differences between architectures so that Architectures and Solutions can be re-used, Also EC is

• A view of the Architecture Repository
• Methods for classifying architecture and solution artifacts
• Re-use a industry standard solution where ever its possible rather than re-inventing a wheel , in other words a Telecom industry has a well established billing software and solution for both its retail , inter connect and value based services , use those solutions ( softwares ) rather than writing your own home grown software solution, this helps in business continuity as you are re-using industry standard experience rather than re engineering your own solution.
• Some times even the language specific to industry standard counts a lot for example you talk of inter connect billing people in telecom domain understand it , where as if you invent new words to coin the same you would end up confusing the stake holders / partners associated with
• Generalize a Specific Solution or Customize a Generic Solution based on External factors that influence Architecture Context

1. Architecture Continuum

Architectural Continuum = Foundation Architecture + Common System Architecture + Industry Architecture + Organization Architecture

where

Foundation Architecture provides direction and strategies for products and services, Very High level, Generic,

Common System Architecture create an architecture useful for building common and reusable solutions across a wide number of relevant domains, Some of the examples are Security Architecture, Email Architecture and Network Architecture

Industry Architecture is more Industry Specific , for example telecom industry might follow some standards no matter which operator operates in which country, Active Store Arch for Retail Industry, eTOM for Telecom Industry

Organization Architecture is more related to Specific Enterprise or Organization, Tailored for Specific Org Needs, Each Business Divisions might have different needs , and each Divisions might have different Org Specific Architecture. They are more requirement specific,

2. Solutions Continuum

Solution Continuum = Products and Services + System Solutions + Industry Solution + Organization Solution

example

Products : Need to be procured based on Approval chain

Services : Need to be top class including In Person Training with Course Material

System Solutions : Only Certified and Branded Systems need to be implemented

Industry Solutions : Procure Re-usable components from Industry leaders if it is better choice than to develop your own

Organization Solutions : Implementation of the EnterpriseArchitecture that provides therequired business functions

All working together in Enterprise Continuum

Answer 4

Architecture Continuum provides a framework or methods for classifying Architectural assets in a manner that makes accessing and communicating them to various stakeholders easy and understandable. The issue here is that Architectural Artifacts are build from various models, and this is bound to come up with assets descriptions with different notations, which is bound to make communication and understanding difficult. So to me its more of HOW Architectural Artifacts are stored in the Architecture Landscape.

On the other hand Architecture Repository focuses at WHERE physically the Architectural artifacts/Assets are stored and to some extend WHAT aspects of it are stored.

Answer 5

Architecture Repository is the list of Architecture Artifacts.

Enterprise Continuum shows your way how to participate in the Enterprise life - how and when to update Architecture Repository for example.

Answer 6

First of all, Enterprise Continuum is not a physical repository like Architecture Repository. It's a kind of a report on the underlying physical architectural assets classified according to your convenience. One way to do is to classify them as Foundation, Common System, Industry and Org Specific. EC is like querying the underling architecture repository in an Oracle database for example.

Answer 7

The Enterprise Continuum is the way HOW you sort your architecture documents. The following pictures illustrates the Enterprise Continuum concept: How does the Enterprise Continuum work?

The Architecture repository is the actual collection of architecture documents of an enterprise. It is organized with the structure that the Enterprise Continuum suggests.

Other TOGAF concepts are explained here: https://www.digitalroadmap.management/blog/2019/1/13/what-is-togaf

Answer 8

Here is my 2 cents worth.

Enterprise Continuum is the collection of documents not just within architecture framework but can be used for the architecture to improve efficiency, speed and accuracy. The contents are stored in Enterprise Repository which will also store Architecture Repository

Architecture repository is specific to the project at hand which is under the complete control of EAs. This includes artificats and deliverables from the ADM cycle.

Answer 9

To Answer your question in layman terms

Architecture repository is a large document, containing all outputs of all projects related to the architecture.

Enterprise continuum is another document classifying the contents of the architecture repository evolving from the most basic foundation architecture to organization architecture (from basic to application specific) and providing information about the relationship between these objects.

Note That: Architecture Continuum inter-relating solutions continuum as well

Answer 10

The following description was helpful in differentiating the framework from the repository.

From TOGAF 8 definition which I find clearer than TOGAF 9 definition stated below.

The practical implementation of the Enterprise Continuum will often take the form of a repository that includes reference architectures, models, and patterns that have been accepted for use within the enterprise, and actual architectural work done previously within the enterprise. The architect would seek to re-use as much as possible from the Enterprise Continuum that was relevant to the project at hand. (In addition to the collection of architecture source material, the repository would also contain architecture development work-in-progress.)

The criteria for including source materials in an organization's Enterprise Continuum will typically form part of the organization's IT governance process.

The Enterprise Continuum is thus a framework (a "framework-within-a-framework") for categorizing architectural source material - both the contents of the architecture working repository, and the set of relevant, available reference models in the industry.