Need for Service Oriented Architechture

Need for integrating an existing business model with new business model: Upgrading the existing business model is a need to adapt to the new customer bases and business partners. Sharing the IT system with another organization is the new trend in business. A practical example could be any online auction sites like the ebay where other third party organizations will register and try to sell their products their by increasing their customer base. In this direction SOA offers a cost effective solution. Legacy systems developed based on a earlier business model might need to be upgraded in order to integrate with the systems developed with new business models. The complexity of this whole process is the biggest challenge for the organizations.

Need for reusability: SOA implements functionalities as services. Each service describes a unique functionality. Organizations IT system is composed of a collection of these services, each one of which can evolve and change.This can be better explained with the following example. Assume there is an iphone for auction. This iphone could be available for auction either through ‘ebay’ or ‘sedo’ or ‘bidz’ or any other auction sites. When users click on this iphone link through any of these auctioning sites, in all scenarios it has to be redirected to the same web page which gives the details of the auction. This single web page which describes the product can be implemented as a service. Here the single web page service is used by multiple auction sites.

Need for Agility:   The ability to adapt rapidly, and taking advantage of change. For example, when a new opportunity arrives (e.g., a new product offering) or a business condition changes (e.g., a merger), companies need technology solutions to support this changing environment. By service enabling systems – grafting an XML and Web services interface onto existing applications – executives can access data that they need to make decisions more quickly, and firms can service their customers more effectively than before.

Efficiency:  Leveraging existing resources as much as possible. It is financial burden for the organization to reinvest time and money to recreate existing software, whether decades-old mainframe, 10-year-old client/server, or two-year-old Internet computing applications. By service-enabling these systems, companies can keep them in place but make it easier to access them or integrate them with other applications. This is achieved, where SOA provides an interface for all the systems, suitable for communication with other systems involved in the process. SOA can even create new solutions by combining existing service-enabled applications into more comprehensive, multiservice solutions called composite applications

Terminologies

Legacy system: is an old computer system or application program that continues to be used because the user does not want to replace or redesign it.

Business model: is a conceptual tool that contains a big set of elements and their relationships and allows expressing the business logic of a specific firm.

Also, a business model is simply a working description that includes the general details about the operations of a business. 

Customer base: is the group of current clients and consumers that a business serves.