Enterprise architectures
Enterprise architecture is used by many people in different layers of the organization and can have a
different meaning for every one of them. It can be directly linked to the model from Henderson and
Venkatraman because the strategic alignments should fit with the enterprise design architecture
(both address how the designs of business and IT affect performance). The architecture is also linked
to the business model of the firm. Together they define how the value is created.
Five core components comprise an EA:
- As-is: The current state assessment of the organization
- To-be: The future state and, generally, the main focus on an EA assignment
- Migration plan: Without a viable route from as-is to to-be the architecture has already failed
- Principles: The 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 part of the ‘living’
architecture.
- The field began to address two problems; system complexity and poor business alignment.
Together this led to increasing cost and less value adding.
Enterprise architecture is a tool to get grip on what the organization is and how it uses IT. When you
know this, you can use this to organize your security. The architectures of a firm consists of many
models.
Four enterprise architecture methodologies dominate the field. These methodologies together cover
the enterprise architecture process. Bits and pieces from each of the methodologies and modify and
merge them according to the specific needs of your organization.
- Zachman framework
- The open group architecture framework (Togaf)
- Federal enterprise architecture (FEA)
- Gartner
There are two main views of enterprise architecture:
- John Zachman: Modeling view
- Jeanne Ross: An executive-level guide for digitization
Lecture 2: Zachman framework
Models are also called artifacts. EA is a combinations of tens to thousands artifacts (lists, tables and
diagrams), that describe a business and its systems. An enterprise architecture framework states
what artifacts or what types of artifact should be created and in what order and by whom.
EA as a framework (Zachman): Describing an information system. The Zachman framework shows
how everything fits together and how it relates to its surrounding environment. It specifies what
types of models should exist to have a complete picture of an enterprise or IT organization. It can be
used to structure the description of any complex object. It compares the perspectives produced by
an architect:
Benefits of Zachman Framework:
- Organized the current artifacts
, - Predicted the need for unknown artifacts
- Scope: It corresponds to an executive summary for a planner or investor who wants an
estimate of the scope of the system, the costs and how it would perform.
- Enterprise model: Sketch of the final model from the owners perspective. Together with the
scope it defines the business architecture.
- System model: translation of the specifications. The data elements and functions are
determined. It defines the system/application architecture.
- Technology model: must adapt the information system model to the details of the
programming languages. It defines the technology architecture.
- Components: The detailed specifications that are given to programmers who code individual
modules without being concerned with the overall context or structure of the system.
- Functioning enterprise: What users see. Graphic user interface (GUI).
Each model or artifact has their own grammar.
The stakeholders are defined as rows:
- Executives
- Business managers
- Architects
- Engineers
- Technicians
- Users
Enterprise architecture is used by many people in different layers of the organization and can have a
different meaning for every one of them. It can be directly linked to the model from Henderson and
Venkatraman because the strategic alignments should fit with the enterprise design architecture
(both address how the designs of business and IT affect performance). The architecture is also linked
to the business model of the firm. Together they define how the value is created.
Five core components comprise an EA:
- As-is: The current state assessment of the organization
- To-be: The future state and, generally, the main focus on an EA assignment
- Migration plan: Without a viable route from as-is to to-be the architecture has already failed
- Principles: The 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 part of the ‘living’
architecture.
- The field began to address two problems; system complexity and poor business alignment.
Together this led to increasing cost and less value adding.
Enterprise architecture is a tool to get grip on what the organization is and how it uses IT. When you
know this, you can use this to organize your security. The architectures of a firm consists of many
models.
Four enterprise architecture methodologies dominate the field. These methodologies together cover
the enterprise architecture process. Bits and pieces from each of the methodologies and modify and
merge them according to the specific needs of your organization.
- Zachman framework
- The open group architecture framework (Togaf)
- Federal enterprise architecture (FEA)
- Gartner
There are two main views of enterprise architecture:
- John Zachman: Modeling view
- Jeanne Ross: An executive-level guide for digitization
Lecture 2: Zachman framework
Models are also called artifacts. EA is a combinations of tens to thousands artifacts (lists, tables and
diagrams), that describe a business and its systems. An enterprise architecture framework states
what artifacts or what types of artifact should be created and in what order and by whom.
EA as a framework (Zachman): Describing an information system. The Zachman framework shows
how everything fits together and how it relates to its surrounding environment. It specifies what
types of models should exist to have a complete picture of an enterprise or IT organization. It can be
used to structure the description of any complex object. It compares the perspectives produced by
an architect:
Benefits of Zachman Framework:
- Organized the current artifacts
, - Predicted the need for unknown artifacts
- Scope: It corresponds to an executive summary for a planner or investor who wants an
estimate of the scope of the system, the costs and how it would perform.
- Enterprise model: Sketch of the final model from the owners perspective. Together with the
scope it defines the business architecture.
- System model: translation of the specifications. The data elements and functions are
determined. It defines the system/application architecture.
- Technology model: must adapt the information system model to the details of the
programming languages. It defines the technology architecture.
- Components: The detailed specifications that are given to programmers who code individual
modules without being concerned with the overall context or structure of the system.
- Functioning enterprise: What users see. Graphic user interface (GUI).
Each model or artifact has their own grammar.
The stakeholders are defined as rows:
- Executives
- Business managers
- Architects
- Engineers
- Technicians
- Users
