System Integration

System Integration (SI) is a term which is in practice used in two meanings:

In a narrower technical approach, it is an integration of various technical components of an information system, i.e. applications (systems) into one whole. The aim is such that information system architecture, as a whole, which effectively supports business processes in an organization.
In a broader approach, the system integration refers to the entire process that is necessary for the effective operation of especially larger information systems.

System integrator is a provider of system integration. His task is to ensure both the integration and coordination of individual vendors and responsibility for the functionality of the entire information system. The approaches to the integration of the information system in the enterprise had been developed for years, depending on how technology progress went on. There are about 4 generations (approaches) to the system integration:

Data Replication
ETL (Extract Transform Load)
EAI (Enterprise Application Integration)
EII (Enterprise Information Integration)

Use of the system integration in practice: Due to increasing complexity, interdependence of modern enterprise information systems, it is important to be able to properly link and network the parts. System integration in some form is applied in most medium and in all large organizations. System integration may be performed by some people from the team within the competence of the IT manager (CIO) or it can be performed as an outside service, provided by the system integrator. System integration is oan ngoing, never-ending task of managing large-scale enterprise information system, or it may take the form of an one-off project that will allow its breakthrough improvement.

System Integrator plays an important coordinating role in the systematization of a client’s requirements on the development of IS, quality management and control of project outputs. He manages, coordinates and assumes an effective guarantee for the realization of business objectives in terms of deadlines, scope of solution, costs, budget and quality. System Integrator is the guarantor of the proper solution design and clear specification of its assigned implementation. He coordinates the different requirements for input and output to deliver an overall functional solution to the client.

Properly designed solutions usually consists of:

Simplification of the existing integration architecture (reducing the number of interfaces between systems)
Lower costs of modification of existing systems and applications
Lower costs of implementation and integration of new systems and applications
Increased automation of business processes, resulting in lower costs and higher processing speed
Possibility of easier integration with external subject systems

Levels of integration:

From the perspective of IS architecture, the integration can be implemented on several levels:

Integration at the user interface (presentation layer)
Integration at the application layer
Integration at the data (persistent) layer
Integration between different layers of IS architecture

Integration styles - represent general approaches to the integration of information systems or applications, respectively representing the possible ways of communication between systems. From this perspective, there are several basic approaches:

Integration at the data (persistent) layer:
- Transferring Files
- Shared database
- Shared files
- Data Replication
- ETL processes
Integration at the application layer:
- Remote Procedure Call (RPC)
- Messaging
Integration at the presentation layer:
- Portal Solutions

Integration architecture solves the question, how, in particular, the links between different systems or applications will be arranged. Among the most available characters belong: