Legacy Integration Supplement: A Chance to Address Tactical Objectives

by Nathaniel Palmer
August 1, 2004

Today, IT must keep pace with demands for new applications and capabilities. This is in addition to new mandates for governance and accountability and the growing need to rationalize increasingly diverse sets of applications and data. Within this context, legacy systems integration presents a host of issues likely to be familiar to any CIO—growing project backlogs and expanding system complexity as code changes cascade through myriad applications and data structures. Compounding this is a mandate to do more with less—deliver greater functionality and manageability in the face of declining IT budgets.

In light of all this, it should be no surprise that adopting a strategy aimed at reducing the cost of integration has become a CIO’s career necessity. Whether it’s as little as 35 percent or as much as 70 percent of the IT budget, integration spending is one of (if not the) single greatest drains on “discretionary” dollars. The mandate for integration was a boon for EAI software over the last five years. Following massive investments in software and hard coding, however, many earlier EAI investments have run nearly full-circle and now often present their own legacy burden. While the degree of necessity for integration has grown significantly, few CIOs would brag about the flexibility of their EAI infrastructure.

Although traditional EAI remains an option for integrating applications, the quiet-yet-ubiquitous expansion of Web Services has opened the door to a new realm of integration possibilities, those which offer the chance to redefine the notion of “application integration.” The fact that pieces of information may be needed in the same application or context does not mean it must be integrated at its source. Most often, it is better that information remain in its native application location, due to both the cost and effort that would otherwise be involved in integration, as well as maintaining the original integrity of information.

Once information is accessible (i.e., parameters are known about its location and context), it is more broadly usable and more efficiently accessed than if it were integrated through EAI. Web Services, specifically integration based on Web Services standards and a Service-Oriented Architecture (SOA), present an opportunity for incrementally exposing legacy systems and data as a library of “consumable” services— application resources that can be located and accessed by applications in a way parallel to how users interact with application interfaces. While Web Services has by now been overexposed as “the next big thing,” the opportunity it offers for incremental integration has led to a parallel “quiet revolution” of sorts, distinguished by an exponentially growing number of application resources being exposed and published as services.

Consider all the systems and sources of data you use in any given day. For many firms, it would take years to rationalize all the places where business data might be found. However, by knowing where to find the data and how it is described, it can be left intact and usable for multiple purposes. This capability has been enabled by the use of Web Service-standard interfaces, which combined with capabilities such as process management and enterprise portals, has notably extended the usefulness of legacy applications. Additionally, this combination of capabilities has greatly reduced the cost of integration and maintenance by allowing legacy systems to remain largely unchanged and accessible by other systems (through Web Services interfaces).