What is EAI Architecture?

Enterprise Application Integration (EAI) typically divides the world into "point-to-point" or "hub-and-spoke".

Organizations often have developed piecemail integrations incrementally from one application to another, that is, so-called "point-to-point" application integrations. These incremental integrations span a variety of tools, and may be occasionally conflicting, since the integrations and data aren't viewed as a coherent, shared resource.

Forward-looking companies work toward a "hub-and-spoke" or enterprise approach. Data sources and owners are defined, integrations are centrally controlled at the hub, and target systems are registered. This probably sounds, and rightly so, very similar to data warehousing Extraction-Transformation-Load (ETL) architecture -- especially since a datamart often molds diverse data into a single "version of the truth."

Suppose the company acquires a new business. The new business is just one more spoke on the company hub. Data from the new business should flow (once the spoke is implemented) into the hub and be published as necessary through the enterprise. For example, sales data from the new business should flow into the existing company sales datamart.

A concise chart comparing the hub-and-spoke and point-to-point approachs is found at http://www.e-in.co.nz/Comparison.htm

Michael J. Schroeck provides a general discussion in his March 2000 article (part of his regular series "Insights from the Front Line"): "Increasing ROI with Enterprise Application Integration" at http://www.dmreview.com/article_sub.cfm?articleId=1951

A more detailed discussion including topics of messaging, business-to-business (B2B) and application-to-application (A2A) integration is found in the Jan 6, 2001 article "Pulling Together" by Stuart Lauchlan at http://www.cbronline.com/cbr_archive/4cc44c44708b648f80256d350047cee4