Over my last two articles, I have laid a foundation for a Service Oriented Architecture (SOA) as the enterprise architecture of the globally integrated enterprise and focused on how to define and establish the business side of the enterprise through a well defined business architecture . Before diving into the IT side of the enterprise, this article discusses how to ensure that the IT aligns with business through architecture.
Figure 1 shows the different dimensions of defining a solution – moving from business architecture through a definition of the application architecture, and finally the implementation of the application through a technical or infrastructure architecture. As we have seen in my previous article, the business architecture focuses on defining the strategy and associated processes. The best practice (in the context of SOA) models the business as a set of cohesive and loosely-coupled components that can be combined as a network to support the underlying business activities and that can be shared across the enterprise. These business components combine similar activities resulting in increased flexibility and efficiencies. Furthermore, the business component allows a natural transition to a services view and can be elaborated by modeling the underlying business processes. Typically, the elaboration of the business model also includes a definition of the underlying information (or data) models that are needed to support the business. This information model defines the main business entities and the relationship between these business entities. The business information model provides the foundation for consistency and integration among the various business components and processes.
The application architecture further elaborates services required to implement the defined business model and process. In particular, the services required to implement the business model and process are defined as applications that can be realized using existing legacy, packaged and remote applications and services. The application architecture also elaborates the way that consumers of the business services interact with the process and applications – as defined by the user interface and interaction mechanisms (e.g. via portals, browsers, and mobile devices.)
Finally, the application architecture is implemented or realized using the technical or infrastructure architecture. This architecture shows how the processes, services and applications are mapped on the existing middleware and hardware platform. The focus is in realizing the non-functional requirements of the business, including high availability, performance, and scalability. The technical architecture is also concerned with IT optimization, and includes considerations for virtualizing available resources and defining the policies to provision these resources to applications as needed. Increasingly the focus on the technical architecture also includes considerations for environmentally friendly and energy efficient Green Data Centers.
Author: Mahesh H. Dodani, IBM, U.S.A.