When software applications became larger and larger, people such as Shaw and Garlan coined the term software architecture. This notion of architecture deals with the key design principles underlying software artefacts. In the 1980s and 1990s, people became aware that the development of information technology (IT) should be done in conjunction with the development of the context in which it was used. This led to the identification of the so-called business/IT alignment problem. Solving the business/IT alignment problem requires enterprises to align human, organizational, informational, and technological aspects of systems. Quite early on, the term architecture was also introduced as a means to further alignment, and thus analyzes and solves business?IT alignment problems, Recently, the awareness emerged that alignment between business an IT is not enough, there are many more aspects in the enterprise in need of alignment. This has led to the use of the term architecture at the enterprise level: enterprise architecture.

In 1995 we started our study of enterprise architecture – we just did not know it. At the time we thought we were studying information technology infrastructure transformations. In 1998 we thought we were studying enterprise system implementations. In 2000 it was e-business. But sometime in 2000, we recognized that each of these studies examined basically the same thing: Enterprise Architecture.

Enterprise architecture is the organizing logic for business processes and IT infrastructure reflecting the integration and standardization requirements of a company's operation model... The key to effective enterprise architecture is to identify the processes, data, technology, and customer interfaces that take the operating model from vision to reality.

An enterprise architecture can be thought of as a "blueprint" or "picture" which assists in the design of an enterprise. The enterprise architecture must define three things. First, what are the activities that an enterprise performs? Second, how should these activities be performed? And finally, how should the enterprise be constructed? Consequently, the architecture being developed will identify the essential processes performed by a virtual company, how the virtual company and the agile enterprises involved in the virtual company will perform these processes, and include a methodology for the rapid reconfiguration of the virtual enterprise.

Issues of quality, timeliness and change are the conditions that are forcing us to face up to the issues of enterprise architecture. The precedent of all the older disciplines known today establishes the concept of architecture as central to the ability to produce quality and timely results and to manage change in complex products. Architecture is the cornerstone for containing enterprise frustration and leveraging technology innovations to fulfill the expectations of a viable and dynamic Information Age enterprise.

(Enterprise Architecture is) the set of descriptive representations (i.e., models) that are relevant for describing an Enterprise such that it can be produced to management's requirements (quality) and maintained over the period of its useful life.

The presence of an enterprise reference architecture aids an enterprise in its ability to understand its structure and processes. Similar to a computer architecture, the enterprise architecture is comprised of several views. The enterprise architecture should provide activity, organizational, business rule (information), resource, and process views of an organization.

A framework as it applies to enterprises is simply a logical structure for classifying and organising 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 system [with the aim of] rationalising the carious concepts and specifications in order to provide for clarity of professional communication, to allow for improving and integrating development methodologies and tools, and to establish credibility and confidence in the investment of systems resources.

Enterprise architecture (EA) promotes the belief that an enterprise, as a complex system, can be designed or improved in an orderly fashion achieving better overall results than ad-hoc organisation and design. EA is a co-operative effort of designers, analysts and managers and uses enterprise models in the process... enterprise models carry meaning. This resulted in requirements for the enterprise engineering process, which—if not met—can limit the viability of the process. The analysis of the same factors resulted in requirements for improved Enterprise Modelling Tools.

The is about those methods, models and tools which are needed to build the integrated enterprise. The architecture is generic because it applies to most, potentially all types of enterprise. The coverage of the framework spans Products, Enterprises, Enterprise Integration and Strategic Enterprise Management, with the emphasis being on the middle two. The proposal for the architecture follows the architecture itself improving the quality of the presentation and of the outcome. De nitions of Generic Enterprise Reference Architecture, Enterprise Engineering/ Integration Methodology, Enterprise Modelling Languages, Enterprise Models, and Enterprise Modules are given. It is proposed how the above could be developed on the basis of previously analysed architectures (and other results too), such as the , the GRAI Integrated Methodology, , and TOVIE.

To keep the business from disintegrating, the concept of information systems architecture is becoming less of an option and more of a necessity

There always is an architecture, whether it is defined in advance - as with modern computers - or found out after the fact - as with many older computers. For architecture is determined by behavior, not by words. Therefore, the term architecture, which rightly implies the notion of the arch, or prime structure, should not be understood as the vague overall idea. Rather, the product of the computer architecture, the principle of operations manual, should contain all detail which the user can know, and sooner or later is bound to know.

The software architecture of a system or a family of systems has one of the most significant impacts on the quality of an organization's enterprise architecture. While the design of software systems concentrates on satisfying the functional requirements for a system, the design of the software architecture for systems concentrates on the nonfunctional or quality requirements for systems. These quality requirements are concerns at the enterprise level. The better an organization specifies and characterizes the software architecture for its systems, the better it can characterize and manage its enterprise architecture. By explicitly defining the systems software architectures, an organization will be better able to reflect the priorities and trade-offs that are important to the organization in the software that it builds.

The architecture of a system can be defined as the functional appearance of the system to the user.