EAI - Enterprise Applications Integration

1.What is EAI ?

Ans:
EAI or Enterprise Applications Integration can be defined as data that can be integrated from disparate applications regardless of the platform, allowing the sharing of business processes amongst multiple organizations.
This can be put it in another ways as -
" Enterprise Application Integration (EAI) is an integration framework composed of a collection of technologies and services which form a middleware to enable integration of systems and applications across the enterprise."

2. What are the challenges for  EAI?
Ans:
One large challenge of EAI is that the various systems that need to be linked together often reside on different operating systems, use different database solutions and different computer languages, and in some cases are legacy systems that are no longer supported by the vendor who originally created them. In some cases, such systems consist of components that have been jammed together in a way that makes it very hard to modify them in any way. 

3. Mention purpose of EAI?
Ans:
EAI can be used for different purposes:

1. Data integration: Ensures that information in multiple systems is kept consistent. This is also known as Enterprise Information Integration (EII).
2. Vendor independence: Extracts business policies or rules from applications and implements them in the EAI system, so that even if one of the business applications is replaced with a different vendor's application, the business rules do not have to be re-implemented.
3. Common facade: An EAI system can front-end a cluster of applications, providing a single consistent access interface to these applications and shielding users from having to learn to use different software packages.

4.What are the Major categories of EAI?

Ans:
Integration can be at different application layers: 

• Data Level Integration:
  • Batch data transfer, OR
  • On-line propagation of data updates
• API Level Integration:
  • Data is accessed through published API services
• Service Method Level Integration:
  • Common services shared by different applications
• User Interface Level Integration:The controller reacts to the user input. It creates and sets the model.
  • Common user interface (e.g. web based) for unified access to multiple applications.

  5.What are the Advantages of EAI?

Ans:
Advantages of EAI solutions are: 

• Streamlines business processes and helps raise organizational efficiency.
• Real time information access among systems.
• Maintains information integrity across multiple systems.
• Speedier transactions at reduced costs.
• If one of the applications misbehaves and requires to be shut down for maintenance, then with EAI, we can easily “decouple” it from rest of the systems. Which avoids having to bring down other systems.

6.What are the disadvantages of EAI?

Ans:
The main disadvatages of using EAI systems: 

• Constant change: The very nature of EAI is dynamic and requires dynamic project managers to manage their implementation.
• Lack of EAI experts : EAI requires knowledge of many issues and technical aspects.
• EAI is a tool paradigm: EAI is not a tool, but rather a system and should be implemented as such.
• Building interfaces is an art : Engineering the solution is not sufficient. Solutions need to be negotiated with user departments to reach a common consensus on the final outcome. A lack of consensus on interface designs leads to excessive effort to map between various systems data requirements.
• Loss of detail : Information that seemed unimportant at an earlier stage may become crucial later.
• Accountability : Since so many departments have many conflicting requirements, there should be clear accountability for the system's final structure. 

7.What are the main companies which provide EAI tools / software?
Ans: 

• TIBCO
• webMethods
• Vitria
• iPlanet
• MQSeries (IBM)
• iPlanet
• BizTalk (Microsoft)
• WebLogic (BEA)