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March 20, 2003

Virtual Scaffolding

Simultaneously building on and replacing legacy systems requires temporary support

by Ram Reddy

Failure of supply chain management (SCM) projects can result from several causes: lack of executive sponsorship, organizational misalignment, or immaturity of the technology, for example. But most SCM efforts flounder or fail during a particular stage: the transitional phase from the as-is to the to-be state of the system.

This phase has been difficult to define, communicate, and act upon within firms that have complex portfolios of operational legacy systems. From a technology perspective, this transition phase calls for the partial or total replacement of those existing systems. The typical SCM suite implementation (even if done in a modular fashion) lasts anywhere from a few months to a few years. It's during this transition phase, when new systems have to be built on the foundations of existing systems, that implementation efforts often derail.

Recently, many technologies have seemed promising in making this transition easier. These technology categories have included integration servers, enterprise application integration (EAI) technologies, and middleware, to name a few. Despite overpromising and underdelivering, the technologies that survived the economic downturn have matured and now function as virtual scaffolding to allow the implementation of SCM systems on existing legacy foundations.

What Is Virtual Scaffolding?

An analogy from the physical world helps communicate the concept of virtual scaffolding to line management within a company. To add a floor or install new production equipment in a factory, it's necessary to add scaffolding and supporting structures first. These supporting structures serve to insulate and provide stability to other parts of the factory that need to continue operations as usual during the installation of new equipment. Once the new production equipment is in, it becomes part of the existing factory; the supporting structures are then moved to another part of the factory as needed. Physical scaffolding and support structures are absolutely necessary when existing physical structures are modified. A similar type of scaffolding is required when an enterprise seeks to replace legacy systems that enable business processes across the supply chain.

The typical enterprise's portfolio of legacy applications supports heavy transaction volumes. When installing SCM technologies to replace whole or partial legacy systems, it becomes necessary to have virtual scaffolding to isolate and stabilize the high-volume transaction systems during the various implementation phases. Without this form of virtual scaffolding, the technological complexity of legacy replacement becomes quite overwhelming.

When you implement an SCM module, you typically need it to interface with many legacy systems — such as one-way data transfers, two-way data synchronization, or process triggers. It may be easy to manage one module and its interfaces — data, application, workflow, and technology. However, as the number of installed SCM modules increases, these interfaces become expensive to maintain. A greater danger is that the overall SCM implementation effort will collapse as you try to keep the existing foundations stable while implementing new systems. Most SCM implementation projects at this stage have the mythical "Dutch boy trying to plug the dike" as their poster child. Just as one hole is plugged, another breaks open: A legacy interface fails or behaves unpredictably. Soon enough, the new and old systems begin to fall apart. Virtual scaffolding helps reduce the complexity associated with legacy replacement.

EAI'S Unfulfilled Promise

Articles praising the functionality of EAI technologies to link heterogeneous systems (such as mainframe, Web, integrated SCM suites, and so on) have been the norm for the past few years. As most buyers of these technologies have discovered, they overpromised and underdelivered. The functionality these technologies boasted was quite broad. To read some of the early brochures, only modest effort was required to "seamlessly" integrate data, application, workflow, and technology across multiple heterogeneous systems! The reality proved to be quite different.

EAI technologies were difficult to implement and maintain. Their scope was quite broad and inhibited EAI technologies from succeeding. Many firms that tried to use EAI technologies as the virtual scaffolding for the transition phases in SCM implementations were disappointed with their performance. Instead of easing the SCM implementation task, it added yet another complex piece of technology that neither the systems integrators nor internal IT resources could use effectively.