Newsletter for e-Business consultants and practitioners November-December 1999
Editors: Eldar A. Musayev

Irresistible fashion: EAI - Enterprise Application Integration

What it is?

For the last 20-40 years every large company got a lot of applications on various platforms written in different languages and using a number of incompatible technologies. So... how to make them work together? Not out of aesthetic need (yeah, it's nice, but not enough to spend millions), but out of quite practical needs: integration. HR need data from accounting, sales want to know level of inventory, and dealers want to reorder product automatically from their inventory system. This is even not to mention that training becoming a pain and support... it's better even not to start about that...

Elementary mathematics says that if you have N components and need to connect every two of them you have to create N2 connections. However, if you create N+1th component in the middle and connect every two of original components through this N+1th, then you need to create only N connections. For 2 components this mean 2 connections less, for 10 this is already 98 connections less and so on. And this N+1th component is EAI architecture.


Considering the history of EAI (and especially prehistory) there are five steps which brought IT industry to EAI technology.

  1. Companies create (or purchase) separate systems for separate business processes and departments. One for payroll, another for accounting, third one for human resources, etc. The technology grew.
  2. Companies get too many subsystems which does not work together. As a result promotion in human resources should be reentered in payroll and separately in accounting… Not the easiest way to do that. The need appeared.
  3. Some companies-developers of separate packages started to integrate their separate products. However because each client is unique integration became loose, flexible, allowing to adapt the system to a client requirements. Companies started to upgrade from separate packages to such integrated ones, throwing old ones into the trash. ERP was born.
  4. Despite the process on step 3, many companies still has large incompatible chunks of IT, and each one represent quite an investment, which is not easy to throw out. Besides, ERP companies got a vision of the world dominance and started to charge sky-high rates for their products and consulting services. As a last drop to overfill this cup, some clever minds noticed that it is rare occasion when even some ERP does everything in a best way. More often one system does one thing the best, another does better something else, and so on. "Best-of-the-Breed" ideology was born.
  5. The Demand created the Offer. Instead of (and in addition to) embedded integration, new products appeared specialized in connecting everything with everything. EAI was born.

Why this is so important?

In short there are three major reasons:

  1. Too many large and middle-size companies have this problem.
  2. IT non-proficient management (which means majority U.S. large corporations) thinks that it's cheaper to integrate than redo. And sometimes it's true.
  3. So, it's a lot of money.

A different question is why this need arose. According to AberdeenGroup there are 5 major reasons for this (October 1998 data):

  1. Get new applications into production quickly (38%).
  2. More information beyond traditional confines (20%).
  3. Expand Supplier and Customer relationships (18%)
  4. Integrate a Best-of-Breed world (14%)
  5. Mergers and acquisitions (10%)

    With a new law, permitting banks, insurance companies and brokers to be within the same company, it's likely that last reason (mergers and acquisitions) will become significantly more important. Also these 5 reasons hide the sixth, semi-technical reason:
  6. eBusiness demands web-style thin-client front-ends to existing applications, which were not created with either Internet or intranet in mind.

Definition of EAI

There is a number of opinions on what EAI really is. To avoid religious wars it's better to know most of definitions and use appropriate ones when applicable. Definitions include:

  1. Just it: Enterprise Application Integration.
  2. The process of integration of various applications within (sometimes extended) enterprise. Extended enterprise means a company and it's partners.
  3. Software tools to integrate different applications including legacy applications on mainframes and midrange computers written in obsolete languages like COBOL.
  4. Software tools to integrate various diverse applications.
  5. Architecture and/or code which performs this integration.

Apparently the meaning of EAI changes dramatically, depending on which definition you use. For example IBM WebSphere application server and CORBA tools are EAI tools by definition 4, but not by definition 3. At the same time "screen scrapers" fit into definition 3 and does not go well with definition 4. Effectively this means that almost everybody can claim to be part of EAI by simply using a more convenient definition.

Some tools for EAI

Here are some tools for EAI offered by various software companies. Notice, however, that this list is neither complete nor representative.

Active BusinessWare CrossWorlds Neon
Rendezvous SmartSockets dcXchange MitemView
GenevaIntegrator Info*Engine Mercator BEA Link
AppConnector Agility    

Recommended readings

Start from the Web site of EAI Journal:

After that simple search on AltaVista will return tons of web-sites dealing with (and selling) various software tools claiming to be tools for EAI.

And if this is not enough try books:

Enterprise Application Integration Addison-Wesley Information Technology Series) David S. Linthicum / Paperback / Published 1999
Enterprise Application Integration with CORBA Component and Web-Based Solutions Ron Zahavi, David S. Linthicum / Paperback / Published 1999
Enterprise-Wide Software Solutions : Integration Strategies and Practices Sergio Lozinsky, Paul Wahl (Foreword) / Paperback / Published 1998
Enterprise Application Integration at Work: How to Successfully Plan for EAI William Ruh, et al / Paperback / Published 2000