Application integration in the Web
Replace a mainframe system by a new IT architecture
This story is part of the Internet revolution. Companies that had started their businesses early enough using mainframe computers were sooner or later confronted with the overwhelming success of new architectures in hardware and software alike. Replacing mainframes has always been an enormous challange and the first attempts often failed due to a number of reasons: misconception about the new opportunities, resistance within the organisation, insufficient knowledge about the own business and mismanagement of risks, just to mention a few.
Our customer, a globally leading provider of insurance expertise in the area of the automotive industry, was already aware of numerous traps when its second migration attempt was started. The project was set up more cautiously, with a slower pace and a lot of attention.
It was only during the agile development that the target architecture was finalized: J2EE, 3-tier, web interface, web services, Oracle database.
We started with a pilot. A small set of business functions was discerned - maintenance of some core data. We identified the business process, documented relevant data content in a conceptional data model, analyzed end-user activities - like pressing a button on a terminal -, and created an application as a first draft. Hardware, operating system, database, user interface, application architecture - all new from scratch.
During several cycles of presentations, reviews, discussions and re-implementation we gradually reached a consensus about the new requirements which eventually included a lot of new features and dropped quite many old habits. Still the old look-and-feel was kept for a while - thus letting time for the users to get accustomed to the new technology.
The scope was gradually enhanced and we managed to create a complete replacement of the core database maintenance application while other teams worked on porting different modules. We had the shutdown of the old mainframe already in sight.
A parallel operation was started. The old system was still leading but the actual data maintenance was done in part in the new environment. A permanent data migration enabled the controlled synchronization of the two systems. After a long period of thorough quality assurance and production in parallel, the role of the leading application was switched and the mainframe became first the backup and eventually shut down operation.