Application Integration

The Application Integration (aka Enterprise Application Integration or EAI) pattern serves to integrate multiple Business patterns or to integrate applications and data within an individual Business pattern. The requirements that gave rise to this pattern call for the seamless execution of multiple applications and access to their respective data in order to automate a complex, new business function. Reliable integration of applications - be they legacy stovepipe applications, packaged software applications, or custom applications - requires the use of proven replicable patterns. At its highest level, application integration can be divided into two essentially different approaches:

• Process Integration - the integration of the functional flow of processing between the applications.
• Data Integration - the integration of the information used by applications.

Neither approach is necessarily better than the other. Rather, specific integration requirements dictate which approach best solves a given business problem. For example, the integration of an e-commerce application with an Enterprise Resource Planning (ERP) system for a newly created sales order would most definitely be a Process integration activity. However in the same solution, the master data synchronization of the product catalog between the ERP system and the e-commerce system would be a data integration activity.

Critical to selecting the right Application Integration pattern is an understanding of the integration requirements of the business problem being automated. Some examples of key questions to ask in determining an appropriate EAI design are listed on the EAI Requirements page.

Note
It is worth noting that certain types of integration between applications can be accomplished at the user interface level as well, as covered in the Access Integration pattern.

Enterprise Application Integration is a complicated undertaking. It requires, first, a thorough understanding of the individual applications being integrated, and also the methods used to interconnect them. For a better understanding of the issues and considerations surrounding an Application Integration solution, review any of the following instructional pages:

• The Application Integration general guidelines page provides additional information on choosing this Integration pattern. Business and IT drivers, the e-business context appropriate for this solution type, and additional solution details are discussed here.
• The Application Integration Services page details a set of services and features commonly required in an EAI solution.
• The Application Integration Solution Requirements page can help determine which of the two EAI categories (Process Integration or Data Integration) you should use in designing your e-business solution.

If you have established a sound understanding of the issues relating to your EAI deployment, the next step is to select an Application pattern. The Application Integration pattern can be implemented using any one of nine different Application patterns. These various designs provide solution flexibility to address the specific needs of the business process being automated. These Application patterns are divided into the two categories described above: Process Integration and Data Integration.

• Patterns for e-business naming conventions

• Updated ESB Topology patterns

  Updated: 08-13-2009
  Updated and added new pattern to the ESB Topology patterns.

• Updated Application Integration pattern

  Updated: 08-13-2009
  Added new product mappings to the Application Integration::Broker and Router application patterns using WMB V6 and WESB V6.

• Updated Application Integration pattern

  Updated: 06-12-2006
  Added new product mappings to the Direct Connection, Router and Broker application patterns based on three scenario redbooks.

• Feasibility:
  This material will help you determine the high-level shape of an Extended Enterprise solution, and can ensure your approach looks similar to other successful implementations. Reuse of prior approaches can be an effective way to begin most major projects. Obviously, modifications will be needed for any unique requirements of a given set of partners. This pattern provides a drill-down from high-level architecture to low-level designs and guidance.

• Risk:
  Basing new projects on prior designs and ideas helps to lower the risk of failure. Creating or inventing approaches for each project tends to result in a lower success rate. Frequently, projects begun "from scratch" simply do not work and have major exposures in such areas as security, performance, availability, undefined requirements, and cost overrun.

• Cost-benefit:
  By starting with reasonably complete architecture you can save considerable development time and can obtain assurance that the end solution will have a much higher chance of success. Actual savings will vary, but project teams have realized a 10% to 50% reduction of work effort in their design and architecture phases alone.