Enterprise Architecture

Architecture enables you to accommodate complexity and change. If you do not have Enterprise Architecture, your enterprise is not going to be viable in an increasingly complex and changing external environment - John Zachman

Enterprise Architecture(EA) is a discipline

for proactively and holistically leading enterprise responses to disruptive forces by identifying and analyzing the execution of change toward desired business vision and outcomes. -- Gartner

Enterprise architecture guides technology investment decisions and acts as a bridge between strategy and execution, with a focus on technology. As such, EA is a strategic planning discipline that contributes to organizational change.

Objectives

1. Minimize the risk of miscommunication between business and information technology.

2. Promote business-technology alignment

3. Reduce waste by linking technology investments with business outcomes

4. Solve business problems through innovative use of technology with a longterm view.

5. Advise business and technology leaders as SME on technology-related matters.

6. Analyze the impact of business decision on the technology landscape.

Approach

1. Ensure participation of Enterprise Architects

2. Select EA framework

3. Define the Focus and Scope of EA work

4. Define EA Deliverables

Actors

1. Enterprise Architect

Output

1. Enterprise Architecture Deliverables

Activities

Engage Enterprise Architects

Enterprise Architects are experienced business technology professionals who lead EA activities to ensure that enterprise strategies are aligned with the technology architecture. EAs should be involved in strategy formulation as early as possible.

The responsibilities of EA depend on the company's business-technology model and can be either be responsible, consulted or informed. They are responsible for the outcomes of EA and are consulted on organizational change issues, particularly where technology is involved.

EAs may participate in strategy formulation alongside the strategy facilitator in the following stages:

• Engage: help the facilitator identify relevant stakeholders and capture their concerns

• Diagnose: Identify disruptions and organizational choices to respond to them

• Decide: Identify options and their pros and cons

• Guide: Define EA target state models and guidelines

Enterprise, Solution and System Architecture

Enterprise, solution, and system architectures operate at different levels. Enterprise architecture is more at the conceptual and contextual level. It has a strong strategic focus and a broad view of technology. System architecture is at the other end of this matrix. It is specific to a technology and has a low strategic focus. Solution architecture forms the middle ground by combining enterprise and system architectures. Solution architecture operates at the logical level and has both a strategy and technology focus.

source: mitre.org

Focus and scope of different types of architecture is defined in the matrix below. The scope and focus of EA should align with strategy.

Architecture	Focus	Scope
Enterprise Architecture	Strategy - High Technology - Broad	Enterprise - entire organization
Project Solution Architecture	Strategy - Medium Technology - Medium	Limited to a project
Program Architecture	Strategy - High Technology - Broad	Limited to a program
Business Segment Architecture	Strategy - High Technology - Broad	Limited to a business line
Operations/Process Architecture	Strategy - Low Technology - Specific	Enterprise - entire organization
Application/System Architecture	Strategy - Low Technology - Specific	Limited to a system
Product Architecture	Strategy - Medium Technology - Low	Limited to a product or product line

Levels of Architecture

1. Enterprise Architecture - It is like the City Plan. Architecture from 30,000 feet. EA team works close to strategy and has a broad view of organization. Sets standards and patterns for the organization.

2. Domain Architecture - It is like a town or district within a city. Domain architects are close to the business unit or function strategy and maintains a broad view of the target area. Responsible for architectural decisions for the area.

3. Solution Architecture - It is like a building within the town. Solution architects develop the big picture for a specific solution within a domain.

4. System Architecture - It is like a part of the building. System architects have specific technical focus on a particular system.

EA Deliverables

EA is involved in several deliverables and bears full responsibility for some:

Type	Deliverable	EA Responsibility
Enabling	Current State Models	Responsible
Enabling	Future EA Requirements	Responsible
Diagnostic	Tools and Methods	Responsible
Diagnostic	Future State Models	Responsible
Actionable	Business Roadmap	Participates/shared responsibility
Actionable	Project Charters	Participates/shared responsibility
Actionable	Reference Documents	Responsible
Measurable	Objectives and Key Results	Participates/shared responsibility
Measurable	Project Achievement Reports	Participates/shared responsibility

source: Gartner

EA Frameworks

Zachman Framework

The Zachman Framework is a:

"..visualization schema, which captures the whole EA using a predefined set of models. The models are organized in a matrix with the first dimension describing one particular aspect of an enterprise and the second dimension associating it with a certain stakeholder view" - EAM Initiative

According to John Zachman:

The Framework for Enterprise Architecture (or Zachman Framework) as it applies to Enterprises is simply a logical structure for classifying and organizing the descriptive representations of an Enterprise that are significant to the management of the Enterprise as well as to the development of the Enterprise’s systems, manual systems as well as automated systems

Detailed and fully loaded view of the Framework

Following are the six types of deliverables:

Type of Deliverable	Description	Perspective
Identification	List of relevant concepts. Used to define context and scope from executive's perspective. Consists of lists. Broad view of change with less detail.	Planner's View
Definition	Statement of exact meaning of the concepts. Used to explain the concepts from a business owner's perspective. Consists of business concept models. Broad view with slightly more details.	Owners's view.
Representation	Description or portrayal of the concepts. Used to describe system logic from an architect's perspective. Consists of system representation models from a logical point of view. More detailed view of change. Agnostic of underlying technologies.	Designer's view
Specification	Detailed description of the design and materials used to make something. Used to describe the technologies. Consists of technology specification models. Further details into the technology used.	Engineer's perspective.
Configuration	Arrangement of parts or elements in a particular form, figure, or combination. Used to describe the detailed technical configuration of the actual systems. Consists of tool configuration models.	Technician's perspective
Instantiation	Creation of a real instance or realization of concepts.	Operational view.

Usually these rows are assigned to the following architects: Enterprise architects are responsible for documenting the first two rows. Solution architects are responsible for the 3rd and 4th rows. System architects or designers are responsible for the 5th row. In small organizations, a single architect may document the first four rows combining the work of enterprise and solution architects. The operations team is responsible for the 6th row.

TOGAF Framework

TOGAF

"..provides an approach for designing, planning, implementing, and governing an enterprise information technology architecture." -- Wikipedia

According to CIO magazine, the objectives of TOGAF framework:

• Common language for managing enterprise change

• Avoid lock-in to proprietary solutions by standardizing on open methods for enterprise architecture

• Save time and money and use resources more effectively.

• Achieve proven ROI.

Reference Architecture

Reference Architecture provide solution delivery teams with a set of best practices to make effective design and technology choices -- Gartner

Use of Reference Architecture is a common practice is solution design. Some common examples are reference architectures for CRM, Risk, Human Capital and Digital.

Purpose of Reference Architecture

1. Minimize Solution Designers effort to deliver within time-to-market constraints

2. Align with standards

3. Gradually moved towards Target Architecture

Further Reading

Framework for Enterprise Architecture by John Zachman

Zachman Framework

EAM Initiative - Zachman Framework