Enterprise architecture

Enterprise Architecture is the description of the current and/or future structure and behavior of an organization's processes, information systems, personnel and organizational sub-units, aligned with the organization's core goals and strategic direction. Although often associated strictly with information technology, it relates more broadly to the practice of business optimization in that it addresses business architecture, performance management, organizational structure and process architecture as well.

Modelling the Enterprise Architecture is becoming a common practice within the U.S. Federal Government to inform the Capital Planning and Investment Control (CPIC) process. The Federal Enterprise Architecture (FEA) reference models serve as a framework to guide Federal Agencies in the development of their architectures. The primary purpose of creating an enterprise architecture is to ensure that business strategy and IT investments are aligned. As such, enterprise architecture allows traceability from the business strategy down to the underlying technology.

Companies such as BP, Intel and Volkswagen AG also have applied enterprise architecture to improve their business architectures as well as to improve business performance and productivity.

Enterprise Architecture methodology

The Practice of Enterprise Architecture involves developing an architecture framework to describe a series of "current", "intermediate" and "target" reference architectures and applying them to align change within the enterprise. Another set of terms for these are "as-is", "to-be" and the "migration plan".

These frameworks detail all relevant structure within the organization including business, applications, technology and data. This framework will provide a rigorous taxonomy and ontology that clearly identifies what processes a business performs and detailed information about how those processes are executed. The end product is a set of artifacts that describe in varying degrees of detail exactly what and how a business operates and what resources are required. These artifacts are often graphical.

Given these descriptions whose levels of detail will vary according to affordability and other practical considerations, decision makers can make informed decisions about where to invest resources, where to realign organizational goals and processes and what policies and procedures will support core missions or business functions.

A strong enterprise architecture process helps to answer basic questions like:

Is the current architecture supporting and adding value to the organization?
How might an architecture be modified so that it adds more value to the organization?
Based on what we know about what the organization wants to accomplish in the future, will the current architecture support or hinder that?

A value-based approach to implementing an enterprise architecture is recommended in order to realize quick wins, most notably when the team is first being formed. An analysis of key questions as listed above that provide the most value in an organization should lead the enterprise architecture team towards their highest priority tasks. Teams that spend too much time documenting the plan, without providing real value to decision makers, will be at risk of being disbanded.

Implementing Enterprise Architecture generally starts with documenting the organization's strategy and goals. One part of this work is the company's Operating Model, which describes how the company wants to operate. What are the requirements for Business Process Standardization and Integration.

The architecture process addresses documenting and understanding the discrete enterprise structural components, typically within the following four categories:

Business:
1. Strategy maps, goals, corporate policies, Operating Model
2. Functional decompositions (e.g. IDEF0, SADT), capabilities and organizational models
3. Business processes
4. Organization cycles, periods and timing
5. Suppliers of hardware, software, and services
Applications:
1. Application software inventories and diagrams
2. Interfaces between applications - that is: events, messages and data flows
3. Intranet, Extranet, Internet, eCommerce, EDI links with parties within and outside of the organization
Information:
1. Metadata
2. Data models: conceptual, logical, and physical
Technical:
1. Hardware, platforms, and hosting: servers, and where they are kept
2. Local and wide area networks, Internet connectivity diagrams
3. Operating System
4. Infrastructure software: Application servers, DBMS, etc..

Wherever possible, all of the above should be related explicitly to the organization's strategy, goals, and operations for planning and decision-making needs. The enterprise architecture is most useful when documenting the current state of the technical components listed above, as well as an ideal-world desired future state (Reference Architecture) and finally a "Target" future state which is the result of tradeoffs and compromises vs. the ideal state. Special software is available and becoming increasingly mature to handle the complex task of mapping the enterprise structure.

Such exhaustive mapping of IT dependencies has notable overlaps with both Metadata in the general IT sense, and with the ITIL concept of the Configuration Management Database. Maintaining the accuracy of such data can be a significant challenge. CMDBs are for managing the current state effectively, while EA repositories are employed for corporate project and strategic planning exercises.

Governance is the key process to keep organizational changes on target for meeting articulated goals and strategies defining the future state of the enterprise. Governance can be applied in various strengths from strongly enforced policies, to more subtle means such as the agreement and declaration of IT principles.

Enterprise Architecture requires appropriate positioning in the organization to be successful. One such analogy of city-planning is often referenced for enterprise architecture groups. A common issue for groups that are granted too much authority is becoming known as an "Ivory Tower" group, alienating the teams involved in following architectural governance. A combination of a federated and a small enterprise team can be the most successful implementation, with a focus on democratic instead of authoritarian team involvement.^{[citation needed]}

An intermediate outcome of implementing an enterprise architecture process is a comprehensive inventory of business strategy, business processes, organizational charts, technical inventories, system and interface diagrams, and network topologies, and the explicit relationships between them. The inventories and diagrams are tools to support decision making at all levels of the organization. It is key that the information remain current to be relevant and useful; a process must exist to keep the information "evergreen."

The organization must design and implement processes that ensure continual movement from the current state to the future state, keeping the details current. The future state planning will generally be a combination of one or more:

Closing gaps that are present between the current organization strategy and the ability of the IT organization to support it
Closing gaps that are present between the desired future organization strategy and the ability of the IT organization to support it
Necessary upgrades and replacements that must be made to the IT infrastructure using lifecycle management practices for infrastructure and technologies employed, to address ever changing regulatory requirements, and other initiatives not driven explicitly by any single team in the organization's functional management. One such example is Service Oriented Architecture, an ideal candidate for enterprise architecture team leadership.

Relationship to other IT disciplines

Enterprise Architecture is a key component of the Information technology governance process at any organization of significant size. More and more companies are implementing a formal enterprise architecture process to support the governance and management of IT. However, as noted in the opening paragraph of this article it ideally relates more broadly to the practice of business optimization in that it addresses business architecture, performance management and process architecture as well. Enterprise Architecture is also related to performance engineering, IT portfolio management and metadata in the enterprise IT sense.

The following image from the 2006 FEA Practice Guidance of US OMB sheds light on the relationship between enterprise architecture and segment(BPR) or solution architectures. (From this figure and a bit of thinking one can see that software architecture is truly a solution architecture discipline, for example.)

File:Relation of EA to Segment and Solution Architectures.JPG