1. Week 1: Introduction & defining EA
What is enterprise architecture (EA)? The goal is to better align technical projects with
business needs. Consists of four architectural models:
1. Business architecture = the business mission, strategy, line of businesses,
organization structure, business process models, business functions, etc.
2. Data / information architecture = defines what information needs to be made available
to accomplish the mission, to whom, and how.
3. Application / system architecture = also known as functional architecture. Focuses on
the application portfolio required to support the business mission and information
needs of the organization. At the next level of detail, it addresses the common
business components and business services that can be leveraged by multiple
applications.
4. Technology / technical architecture = defines the technology services needed to
support the application portfolio of the business. It also documents the software,
hardware, and network product standards.
EA challenges over the ages: EA moved from the complexity of an individual system to the
dynamics of multiple systems. Security by design can be considered separate. However,
information security shouldn’t be considered separate, because it is very important to make
sure that your architecture is secure.
Core components of EA:
- As-is = the current state assessment of the organization.
- To-be = the future state and, generally, the main focus of an EA assignment.
- Migration plan = without a viable route from as-is to to-be the architecture has already
failed.
- Principles = guidelines for users of the architecture, such as ‘buy not build’ or
‘adherence to published data standards.
- Decisions log = started during the development of the EA but a key prat of the ‘living’
architecture. Which decisions have we taken during the EA process?
Linking EA & Strategic alignment: both address how the designs of business of IT affect
performance.
,Linking EA & Business models: both define how, who, what, when, and where value is
created (operating
model) and for which
markets (value
proposition). The
business model of a
firm defines the
value proposition
(what value is
offered to whom)
and the operating
model of a firm (how
is the value created).
What is architecture?
- Architecture as model: ‘a set of things’
- Architecture as modelling: ‘making things clear with models’ & ‘reducing complexity
with models’.
IT management = enterprise architects and the IT department (CIO office) play key role in
EA development, advisory and use.
Comparison of the top 4 EA methodologies (Sessions, 2008):
1. Zachman framework (1987): a taxonomy of related models for different stakeholders
and aspects that takes into account both who the architectural artifacts targets
, (business owner, builder, etc) and what particular issue is being addressed (data,
functionality, etc.). Zachman tells you how to categorize your artifacts.
a. EA as a set of models
2. TOGAF (1995): The Open Group Architecture Framework is method for developing
models. It is more of a process than a framework. TOGAF gives you a process for
creating above artifacts.
a. Four architectures (business, application, data, technical).
b. Architecture Development methodology (ADM) to develop the EA for a firm.
c. Using the current (As-Is) EA of the firm, the firm strategy, and industry
(reference) architectures.
d. EA as a method for change.
3. FEA: Federal Enterprise Architecture is an extensive (USA based) EA method
including a taxonomy, a process, a series of models (including reference models, ‘as-
is’ and target (‘to-be’) models), a migration path, EA maturity levels, and success
indicators to assess business value of EA.
a. EA as a method for change.
4. Gartner: Business consulting – EA practice
a. EA as a method for change.
Defining the EA domain (Sessions, 2014):
- Architect = responsible for the design of an architecture and the creation of an
architectural description.
- Architectural description = a collection of products [artifacts] to document an
architecture.
- Architectural artifact = a specific document, report, analysis, model, principle, or other
tangible that contributes to an architectural description.
- Architectural framework = a skeletal structure that defines suggested architectural
artifacts, describes how those artifacts are related to each other, and provides
generic definitions for what those artifacts might look like.
- Architectural methodology = a generic term that can describe any structured
approach to solving some or all of the problems related to an architecture.
- Architectural process = a defined series of actions directed to the goal of producing
either an architecture or an architectural description.
- Architectural taxonomy = a methodology for organizing and categorizing architectural
artifacts.
- Architecture = the fundamental organization of a system embodied in its components,
their relationships to each other and to the environment, and the principles guiding its
design and evolution.
- Enterprise architecture = an architecture in which the system in question is the whole
enterprise, especially the business processes, technologies, and information systems
of the enterprise.
2. Week 2: EA as a framework for design
What is a model?
- Also called artifacts.
- Mostly diagrams, for example visual descriptions of an enterprise. But also tables and lists.
, What is enterprise architecting (EA)?
- Enterprise architecture = a combination of tens of thousands of artifacts (lists, tables,
diagrams) that describe a business and its systems.
- Enterprise architecture framework = states what “artifacts” or what “types of artifacts”
should be created, (sometimes) in what order and (sometimes) by whom.
Zachman Framework (ZF) summary: suggests no artifacts, but only specifies what types of models
you should create to have a complete picture of an enterprise or IT organization. You need 1 diagram
for each cell in the diagram (ZF).
- ZF in 1989 and 1992 is an information system or IS architecture
- ZF in 2008 is an organization → EA.
o Systems are not just information systems, but they can also be manufacturing
systems, transportation systems, etc.
Benefits of ZF:
1. Organized the current artifacts.
2. Predicted the need for unknown artifacts.
ZF stakeholders as rows:
1. Planners = executives
2. Owners = business managers
3. Designers = architects
4. Builders = engineers
5. Sub-contractors = technicians or developers
6. Functioning enterprise = user or operators.