EA

EA is a generic name of frameworks, which were developed by a number of researchers based on Zachman Framework, to describe and organize the entire organization and to improve business and systems.

Overview of EA
EA (Enterprise Architecture) is a methodology to hierarchically organize all components in an organization and to make business administration more efficient by describing an organization, such as a company, government agency, autonomous community, and so forth, in a systematic and comprehensive manner, or a basic concept to realize such an organizational structure. The components include goals of the organization, business process models, business rules, information systems, human resources, etc. EA is a framework to improve business and systems in terms of global optimization, and we can re-examine the complex organization comprehensively and expect to achieve the overall efficiency of the entire organization by organizing the structure of business processes and information systems and utilized technologies etc. in the organization as a whole. In addition, defining the As-Is model and the To-Be model helps us establish a plan to drive the organization toward the ideal status by evaluating the difference of the two models.

Relationship with Zachman Framework
It is said that EA is derived from Zachman Framework. However, Zachman Framework does not have concrete procedures, definitions of outcomes, parts of outcome useful for task execution, etc. Thereby, a number of researchers have developed a variety of frameworks based on Zachman Framework. EA is the generic name of such frameworks.

Expansion of EA's Scope
Just like Zachman Framework becomes widely used not only for information systems but also for the entire corporate activities, the scope of EA has been expanding in stages.

In its first stage, EA was just an architecture of information technologies used in an individual information system and was considered in order to reduce IT cost etc. Then, the scope was expanded so that it was able to be used to plan not only an individual system but also the entire corporate system including cooperation among systems. In the second stage, EA became comprehensive corporate information system architecture, and the perspective of value management was introduced into it. After that, EA started to be utilized to plot plans including business perspective in addition to system and technology perspectives. As a result, in the third stage, it is regarded as the methodology to achieve global optimization focusing on the consistency of business and IT. This is considered as what is called EA today. Some people think that EA covers the entire life cycle of a system, from its birth to death including operation and maintenance of the system and transition to a next-generation system, instead of only the period from the design to completion of the development.

Roles of EA
The primary role of EA is to clarify the current status, especially the gap between business and systems. EA enables us to grasp the overall image through the analysis of the business and entire system in a unified fashion. Based on that, we can comprehensively review the complex organization and thereby can make the most of various information assets, reduce redundant costs, streamline the entire organization extensively. In addition, EA also plays an important role to clarify activities to move toward the ideal status (To-be model) from the current status (As-is model) to establish the improvement cycle. Establishment of EA means to grasp the current situation and then to define the To-be model. To establish EA and continuously review it, standards about data models and security requirements, principles related to IT investments and architecture designs, frameworks to maintain and utilize the EA, and plans to determine priorities about infrastructure construction and IT investments are also required. Another crucial role of EA is to present guidelines concerning long-term design concepts to approach the To-be model and the generation management of technologies based on them.

Overall Structure of EA
A couple of EA frameworks are proposed, and we can grasp their overall structures by understanding the following elements.


 * Driver (Change Factor): Change factors in an environment to motivate EA establishment and improvements
 * Mission and Principle (Basic Guideline): Determine the direction of architecture design
 * Performance Evaluation (PE): A series of indicators to evaluate performance of other four architectures and systems based on them. Performance here is not limited to the processing speed of a system etc., but it also includes various values of systems, such as costs, efficiency, reliability of systems, contribution to business, and benefits for customers.
 * Budget Plan / Development / Evaluation: The way to operate the process that uses the architecture
 * Current Status Review / Goal Definition / Transition Plan: The way to operate the process that establishes the architecture
 * Standardization / Recycle: Activity guidelines to develop systems that observe the architecture
 * Reference Model (RM): A series of terms to be referred to when designing the architecture. In order to promote the adoption of standardized business and systems and realize a highly flexible architecture for the sake of global optimization, reference models are required. Reference models help us improve the quality and admissibility of the architecture.
 * Reference models consist of five types of models, Performance Reference Model (PRM), Business Reference Model (BRM), Service Reference Model (SRM), Data Reference Model (DRM), and Technology Reference Model (TRM). Moreover, each type has layers, which are a large classification, middle classification, small classification, and individual specification.

Structure of EA
Typical EA consists of the following four components.
 * Business Architecture (BA): BA defines the structure or roles of the entire organization and models business processes and information. It is considered as a blueprint that reflects the current and future business. BA is used as a guideline to make a decision about IT investments.
 * Data Architecture (DA): DA shows the data structure necessary for the business. Various aspects of data, such as reusability, security, and quality, are described here. In addition, DA clarifies where the data are generated, how they are processed, when it is deleted, and so forth.
 * Application Architecture (AA): AA defines the functionality of the system that supports business processes and the performance of such a system. It describes the software structure to realize the business functionality and roles and functionality of the system from the business viewpoint.
 * Technology Architecture (TA): TA is an architecture to establish the foundation of the system by means of technologies, including software, hardware, and network. DA defines the IT infrastructure required to stably develop, operate, and extend the information system in the future. More specifically, it defines the technical standards of the entire organization based on the required performance and security level, trends of standardization, capability of the technologies, and so forth. These standards are used as criteria when evaluating whether newly adopted technologies and products meet the requirements for global optimization or not. TA sometimes motivates the changes of EA, such as addition of new technologies to the standard to accommodate the new types of needs.

Relationship with BPM
BPM is to continuously improve business processes towards the global optimization in order to accomplish corporate strategies effectively. Thus, EA can be considered as a tool to effectively realize BPM. A BPM activity is regarded as a practice of EA, especially focusing on parts related to Business Architecture (BA). Although Business Architecture could contain other factors related to business besides business processes, its primary factor is the optimization of business processes. Because BPM includes the implementation of business processes, it also affects Application Architecture (AA) to some extent. However, its impact is relatively small. Therefore, we can consider that BPM is one of the approaches to practice EA focusing on BA.

USA
In the U.S. government, the Department of Defense introduced TAFIM (Technical Architecture Framework for Information Management) in 1994. TAFIM was created based on architectures observing the open system standard in IEEE1003.0 and significantly extended the standard so that it also included the methodology to develop architectures. After it was abolished in January, 2000, The C4ISR Architecture Framework was adopted as a successor of TAFIM, and later the name was changed into DODAF in 2003. DODAF has very concrete and practical descriptions of architectures, and the volume of its framework is very large. Furthermore, it also defines the artifacts to describe system architectures and the notation for them in detail.

In 1999, the U.S. government established a framework to facilitate resource and information sharing among departments and to reduce the cost for IT investments, which is called FEAF. FEAF divides EA into four parts, BA, DA, AA, and TA, and defines each of them. FEAF only defines the abstract framework of business and systems and does not contain many, though not as few as Zachman Framework, descriptions and directions concerning the concrete tasks and artifacts of system development. Thus, FEAF separately prepares the reference models shown below to provide concrete information and facilitate the tasks. Among these models, "E-Gov Enterprise Architecture Guidance (common reference models) Draft Version 2.0" and "Policy / Business Reference Model (BRM)" were published as references for the government projects in February, 2003, and all government agencies follow these guidelines. Also, EA framework adopted by Japanese government is created based on FEAF. Besides, TOGAF (The Open Group Architecture Framework) was created by The Open Group, which is a private standardizing organization, in 1995. This is an open source framework for business developed by mainly private companies and is the most popular framework used in companies nowadays. Introduction of EA is promoted by the enactment of SOX Act in 2002.
 * Policy / Business Reference Model (BRM)
 * Performance Reference Model (PRM)
 * Data Reference Model (DRM)
 * Service Component Reference Model (SRM)
 * Technology Reference Model (TRM)

Japan
In the Japanese government, the Ministry of Economy, Trace and Industry published the guideline for EA establishment in 2003 to promote the reformation of business and systems. It was created based on FEAF in the U.S. and adopts a 4-layer model, reference model and so on. Furthermore, it elaborates some concepts that FEAF only outlines briefly or that are customized to fit Japanese styles. According to the guideline, the purposes of EA include effective and efficient utilization of budgets for e-governments and realization of high-quality government services through the shift to the customer-oriented manner. The guideline for EA establishment is actually used in the e-government building plan.

In addition, in the same way as the U.S. companies, companies in Japan are obliged to do the internal control by J-SOX Act enforced in 2006 and New Companies Act. Nowadays, many companies are working on EA activities, such as the establishment of their own EA, company-wide EA enforcement, re-structure of mission-critical systems, and so on.

Related Articles

 * Zachman framework
 * as-is
 * to-be
 * BPM
 * PRM
 * EA Portal