Most information technology (IT) departments split their time between implementing new and maintaining existing technology. On the software side, most of the focus is on applications supporting business processes. A new application is usually intended to replace an outdated (i.e., legacy) application. However, both will typically run in production until the new application is proven, after which the legacy application is obsolesced (i.e., no longer used) and sunset (i.e., no longer maintained, usually removed).
At least, in theory, that is how it is all supposed to work. However, in practice, legacy applications are rarely sunset. Why?
The simple reason most legacy applications do not go gentle into that good night, but instead rage against the dying of their light, is that some users continue using some of the functionality provided by the legacy application to support daily business activities.
Two of the biggest contributors to this IT conundrum are speed and agility—the most common business drivers for implementing new technology. Historically, IT has spent a significant part of their implementation time setting up application environments (i.e., development, test, and parallel production). For traditional enterprise solutions, this meant on-site hardware configuration, followed by software acquisition, installation, configuration, and customization. Therefore, a significant amount of time, effort, and money had to be expended before the development of the new application could even begin.
Legacy applications are typically the antithesis of agility, but they are typically good at doing what they have always done. Although this doesn’t satisfy all of the constantly evolving business needs of the organization, it is often easier to use the legacy application to support the less dynamic business needs, and try to focus new application development on new requirements.
Additionally, the consumerization of IT and the technology trifecta of Cloud, SaaS, and Mobility has both helped and hindered the legacy logjam, since a common characteristic of this new breed of off-premise applications is quickly providing only the features that users currently need, which is often in stark contrast to new on-premise applications that although feature-rich, often remain user-poor because of the slower time to implement—again failing the business requirements of speed and agility.
Therefore, although legacy applications are used less and less, since they continue to support some business needs, they are never sunset. This feature fracture (i.e., technology supporting business needs being splintered across new and legacy applications) often leaves IT departments overburdened with maintaining a lot of technology that is not being used all that much.
The white paper The Mandate to Modernize Aging Applications is a good resource for information about this complex challenge and explains why application modernization must become the enterprise’s information technology prime directive.
IT can not enable the enterprise’s future if they are stuck still supporting its past. If the sun never sets on legacy applications, then a foreboding darkness may fall and the number of successful new days dawning for the organization may quickly dwindle.