Legacy Modernization – Past, Present and Future
The term “legacy” in most cases refers to applications developed on mainframe hardware. The concept of mainframe computing dates back to the 70s where these platforms were used by almost all large enterprises for their business computing requirements. The emphasis was on accumulating business events throughout the day and later processing them overnight to complete the process. The text-based green front-end applications were normally available only for business desk and data entry. This period saw the entry of multiple mainframe manufacturers such as IBM, UNISYS, Cyber, Bull, and Tandem.
In the mid-eighties to early nineties, a large number of mainframe platforms were migrated to IBM, which was emerging as a leader in the mainframe space.
The advent of UNIX, Windows, Client Server and Web in the mid ’90s changed the entire perception of computing. A large number of systems were migrated from mainframe to client server/Web which was perceived as the silver bullet of the time. While migrations were a success with small to medium workloads, there were also colossal failures. In some cases, the new distributed architectures did not meet the security and performance characteristics of the legacy platforms. Tool-based migrations generated clones of COBOL in Java which did not meet modern design standards. Data migration turned out to be the major cause for overruns.
Another approach to eliminate mainframes was provided by re-hosting technologies. Companies such as Microfocus, Clerity and others produced COBOL compilers that ran on Windows and Linux. These solutions gave immediate cost benefits for standard COBOL-based workloads. However, re-hosting environments using legacy technologies — Telon, MARKIV, IDMS, Supra, FOCUS, IMS and many others — was not straightforward.
IBM and third-party vendors also created mainframe integration products that enabled the integration of mainframe applications and databases with Windows/Linux applications. These integration products allowed mainframe business logic to be exposed as Web Services to the outside world. Today, it is common to have a browser-based front-end on the latest UI technologies with back-end on the mainframe. A large number of legacy integration projects were initiated in the 2000s.
In today’s Digital Age, consumers use a whole new range of multimedia devices to access the Internet. Businesses want to gather information on the buying and spending habits of these consumers, who in turn demand a compelling user experience while surfing the Internet.
The challenge before organizations is how to leverage their multi-billion dollar past investment in existing systems. This is where IT vendors need to evaluate their expertise and bring innovation in dealing with the requirements of the organization for modernization. The definition of modernization should include capabilities that bring the legacy systems to the new consumer-centric world. These capabilities require modernization or integration of the backend “legacy” systems. Mobility, cloud, analytics, big data need to be looked at from the legacy modernization/integration perspective. The expectation from IT services is to reduce cost, and reuse existing applications and infrastructure.