1) SOA is not a purely technical approach and it doesn’t have to mean Web services:-
Service oriented architecture is not a technology architecture. Business themselves are more important and services that support them. It is an enabler. SOA is better responsiveness to changing business processes. SOA does not mean web services. Web services are part of an SOA strategy. Service definitions are based on other standard protocols. The service will help to determine how it is implemented.
2) SOA can be built using existing infrastructure, process automation is a key virtue of SOA ,SOA architectures can be highly complex , requires a keen understanding of business data and SOA is an evolutionary approach (from components objects etc)
Many organizations build SOA using in existing infrastructure. E.g.:- NET and J2EE, XML, MSMQ and JMS. Service oriented architecture came out of left field. SOA is a natural evolution of both architecture and technology.It is important to look across the enterprise and across the business and processes. It provides a context in which technology decisions can be made. The SOA tools include internet technologies such as HTTP and XPL and integration technologies.
The real value of SOA is as a business automation tool. It can be defined in terms of the processes or activities the organizations performance.
SOA architecture is fairly simplistic. E.g.:- Developing a business process flow and identifying the required services. It is important to undederstand the data that is relevant to those processes. An ordering process has several key data artifacts. Each service that participates in the process can understand the data equally.
With existing information architecture for organizations may not be a big issue. Each service or process is implemented the associated information’s architecture. It can be involved to include the necessary data artifacts.
3) SOA services properties
a) Services can be simple or compound: – It is a very difficult task to define a service. The service is simple in many cases. Services can also be compound. This means super services are providing a standard interface. Compound services are to be created when an automated process model is itself exposed as a service.
b) There can be multiple layers of automation in SOA: – The characteristic of service architectures is that automation can happened in different layers. Automation is applied to at least two key areas in SOA solutions. The first and most important area is in the business process layer. To create automation the processes are designed the steps within them are linked together. The next important automation layer is in non human interaction or system interaction. It is also important for having different tools. With another application or system different consideration is made for interactions with a human than for interactions.
c) Services should agree on interface standards (both protocol and data):- Standadased method of communicating is important for services. In the SOA world communication is made of two components. The first is the network protocol that services used to communicate. The second component is the data or language of the communication.
d) Services can be outsourced: – Services can be outsourced. This means that when you need a service to handle the submission of regulatory complaints documents to a government authority. You need not build it yourself. Another major consideration is performance. Depending on variety of factors that degenerate your business processes.
e) Services can be built from existing legacy systems and applications: – Many organizations wrongly think the SOA approaches leave little consideration for legacy systems. It is mainframe applications. One of SOA’s strongest value is it allows an organization to reuse mainframe and other legacy assets. This is very important because core business logic and core business data are often locked away in proprietary legacy systems. Mainframes are not the only legacy data source. Mini computer system are enabled here in one way or another.
Eg: -AS/400, VAX and HP 3000
4) Performance is a key concern in SOA systems, The jump to SOA can be difficult and SOA delivery is built on four components
A lot of benefit provides SOA for organizations. Applications are highly segmented in a typical SOA environment. Application and system of performance are important to the business. If the critical processes are identified you can focus on enhancement and performance improvement. In SOA delivery plan there are four components. The first component is to define the business processes. The next component is the SOA architecture and patterns. The third component is the SOA infrastructure. The fourth components are the SOA development program. The move to services architecture is difficult for a variety of reasons. The immediate reason is that a change of SOA is like any other change. It requires a high level of communication and socialization. There may be additional technology issues when the dynamics of change have been overcome. Training the development teams on the technology is the one example for this.
5) SOA is business driven: –With regard to increasing ROI and organizational agility while decreasing burdens a true SOA solution is provide demonstrable business value.
6) SOA is vendor neutral: – This is type of architecture designed to be as independent. Governance has an important and never ending role to play in preserving these aspects.
7) SOA is enterprise centric: – It comes with a heavy governor’s responsibility.
8) SOA is composition centric: – One of the successes of an SOA initiative is the degree to which its services are composed into the solutions.
9) Basic SOA features:- The basic SOA features are,
a) Formal: – Formal means, formal contact presented at a granularity recognized by the user as a meaningful service.
b) Relevant: – SOA is relevant because functionality is presented at a granularity recognized by the user as a meaningful service.
c) Published: – Precise, published specification functionality of service interface, not implementation.
d) Reusable: – Use of Service, not reuse by copying of code/implementation.
e) Abstracted: – Service is abstracted from the implementation.
10) Advantages of SOA basic features:-
a) There is real synchronization between the business and IT implementation perspective: – Business people do not know the IT architecture for many years. Communication with the business ca radically improves with well designed services.
b) A well formed service provides us with a unit of management that relates to business usage: – Enforced service provides us with basis for understanding the life cycle.
c) When the service is abstracted from the implementation it is possible to consider various alternative options for delivery and collaboration models: – Services is abstracted from the implementation. It is entirely realistic and it is assume that certain services will be acquired from external sources because it is more appropriate to acquire them
E.g.: – Authentication services.