Legacy applications are, without doubt, robust and built for long life spans. So why are they failing the fitness criteria?
The reality is that today’s fast-changing digital environment is making markets, customers and boards demand more—exposing the architectural and maintenance limitations posed by legacy applications. This is the key reason why Application Modernization is rising to the top of every CIO’s agenda.
The primary goal of application modernization is to create added business value from existing applications. Application modernization, as a concept, implies migrating from legacy applications to new platforms that have the required business functionality and can integrate with other systems when required. This means, legacy applications must come under the scalpel and get doctored—reused, renewed, consolidated, retired or built anew—to improve their fitness.
Approaches to modernization
Typically, after an organization determines the target environment, examines the existing gaps and points of failure, and identifies the applications (or components) that need modernization, it can adopt two approaches: the Greenfield Approach and the Two-Speed Approach.
Greenfield Approach: This approach is prescribed when a complete change in environment is required, driven by the limitations of legacy applications. Here, the team begins from scratch, capturing use-cases, defining requirements and articulating outcomes. The team begins by building the first block of the application and then progressing steadily until all the blocks are in place (See Figure 1), putting in place the equivalent of foundational development. The result is total transformation. This approach is time consuming and often, laborious (See Figure 2).