SOA Definition

A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.

Service-oriented architectures are not a new thing. The first service-oriented architecture for many people in the past was with the use DCOM or Object Request Brokers (ORBs) based on the CORBA specification.

Services
If a service-oriented architecture is to be effective, we need a clear understanding of the term service. A service is a function that is well-defined, self-contained, and does not depend on the context or state of other services

Connections
The technology of Web services (new window) is the most likely connection technology of service-oriented architectures. Web services essentially use XML (new window) to create a robust connection.

For more SOA Service Oriented Architecture Definition, visit service-architecture.com

Service-oriented architecture (SOA) definition

SOA definition

A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.

Service-oriented architectures are not a new thing. The first service-oriented architecture for many people in the past was with the use DCOM or Object Request Brokers (ORBs) based on the CORBA specification. For more on DCOM and CORBA, see Prior service-oriented architectures (new window).

Services
If a service-oriented architecture is to be effective, we need a clear understanding of the term service. A service is a function that is well-defined, self-contained, and does not depend on the context or state of other services. See Service (new window).

Connections
The technology of Web services (new window) is the most likely connection technology of service-oriented architectures. Web services essentially use XML (new window) to create a robust connection.

The following figure illustrates a basic service-oriented architecture. It shows a service consumer at the right sending a service request message to a service provider at the left. The service provider returns a response message to the service consumer. The request and subsequent response connections are defined in some way that is understandable to both the service consumer and service provider. How those connections are defined is explained in Web Services explained (new window). A service provider can also be a service consumer.

Source: http://www.service-architecture.com/web-services/articles/service-oriented_architecture_soa_definition.html

Defining SOA service-oriented architecture

Defining SOA service-oriented architecture

This section will address defining SOA service-oriented architecture and look at what makes it unique.

Key elements

It's important to understand the key elements of service-oriented architecture SOA. With that goal in mind, let's begin by breaking down the service-oriented architecture SOA acronym into its core elements. We'll start with the last part first: architecture.

Let's look at the architecture in the context of service-oriented architecture SOA. Typically in software, architecture defines the overall definition and intercommunication of various high-level components. In simple terms, it's how we break down a solution into logical units and how they'll interoperate. In this sense, SOA represents an architectural approach that's focused on the definition and interaction of services.

Because service-oriented architecture SOA is a set of architectural principles, you can't go out and buy one. You may be able to buy middleware components that provide enabling technologies and core services. But by themselves, they aren't an SOA.

Let's move on to another piece of SOA: service-oriented. Service-oriented means that we'll center our solution architecture on a collection of services. If you've had experience with Object Oriented Design (OOD), this may seem familiar. In fact, these two approaches have many elements in common.

A service is a way of thinking about and organizing business functionality so it can effectively stand on its own. The service-oriented architecture SOA approach considers this functionality in terms of service providers and service consumers.

Service providers offer functionality as a set of interfaces to the service capabilities they provide. Service consumers will access the service capabilities provided by the service provider. These consumers may be an application or even a service provider. For example, a checking account service may offer a set of functionality relating to a checking account. This account may offer the ability to make a deposit, make a withdrawal, create a new account, etc. Notice that the capabilities we've described are very specific to the concept of checking account service. Also notice that we haven't yet said whether this service is provided by some banking software, by an ATM machine, by a teller in a bank, or all of the above.

Some may argue that this definition of service-oriented architecture SOA is just the latest way to describe and model application functionality. But it is important to realize that most applications today have been built with an end user in mind. To that end, an application may encapsulate a group of tasks that are related in some ways but are also discrete.

One of the key distinctions of an SOA service-oriented architecture is the fact that the consumer of some application functionality may in fact be another application or service. While human users tend to prefer all functionality aggregated together and accessible through one user interface, other applications don't have the same requirement. As a result, it makes sense to have functionality organized around a set of services that can be self-contained and yet can be woven together to create higher level functionality or services.

Once you apply these architectural principles, you'll end up with a set of services that can interact to provide a specific set of functionality with a business benefit. And now re-use comes into play: You could rapidly build another solution that reuses some of these services as well as some additional services that may be required to satisfy the business requirements. In the end, these services are woven into a kind of software ecosystem. Here, they cooperate to achieve a business objective but may also participate in other ecosystems that offer the same service capability for potentially different end solutions.

Service-oriented architecture (SOA) definition

SOA Service-oriented architecture definition

A service-oriented architecture SOA is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.

SOA Service-oriented architectures are not a new thing. The first service-oriented architecture for many people in the past was with the use DCOM or Object Request Brokers (ORBs) based on the CORBA specification. For more on DCOM and CORBA, see Prior service-oriented architectures (new window).

Services
If a service-oriented architecture is to be effective, we need a clear understanding of the term service. A service is a function that is well-defined, self-contained, and does not depend on the context or state of other services. See Service (new window).

Connections
The technology of Web services (new window) is the most likely connection technology of service-oriented architectures SOA. Web services essentially use XML (new window) to create a robust connection.

The following figure illustrates a basic service-oriented architecture SOA. It shows a service consumer at the right sending a service request message to a service provider at the left. The service provider returns a response message to the service consumer. The request and subsequent response connections are defined in some way that is understandable to both the service consumer and service provider. How those connections are defined is explained in Web Services explained (new window). A service provider can also be a service

Source: http://www.service-architecture.com

SOA definitions

Service Oriented Architecture SOA definitions

SOA Service Oriented Architecture is a design for linking business and computational resources (principally organizations, applications and data) on demand to achieve the desired results for service consumers (which can be end users or other services). OASIS (the Organization for the Advancement of Structured Information Standards) defines SOA as the following:

A paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains. It provides a uniform means to offer, discover, interact with and use capabilities to produce desired effects consistent with measurable preconditions and expectations.

There are multiple definitions of Service Oriented Architecture SOA, the OASIS group and the Open Group have created formal definition with depth which can be applied to both the technology and business domains.

Open Group SOA Definition (SOA-Definition)[3]
OASIS SOA Reference Model (SOA-RM)[4]
What Is Service-Oriented Architecture? (XML.com)
What is Service-Oriented Architecture? (Javaworld.com)
Webopedia definition
TechEncyclopedia definition
Object Management Group (OMG ) SOA Special Interest Group definition
WhatIs.com definition
SearchWebServices.com Numerous SOA definitions by industry experts

Though many definitions of Service Oriented Architecture SOA limit themselves to technology or just web services, this is predominantly pushed by technology vendors; in 2003 they talked just of web services, while in 2006 the talk is of events and process engines.

Source: http://en.wikipedia.org/wiki/Service-oriented_architecture