Owing to mergers and acquisitions it is quite common for large financial institutions to have multiple systems with more or less the same functionality. This results in a multitude of systems with differing technologies, all carrying there own license, infrastructure and support costs. Also, these fragmented systems pose obstacles to unified data analysis, usage of BI tools etc.

NIIT, based on its experience with legacy systems, has developed a methodology for decommissioning legacy systems. The replacement systems in many cases have been a package from a third party vendor.

Decommissioning projects typically require a high degree of business involvement which is why NIIT's domain practices (Banking and Finance, Retail, Travel) also have significant involvement in such projects.

The workflow for a typical decommissioning project is as follows. During impact analysis NIIT's Insight code mining framework has been found to be very effective in several situations. For data migration there are two approaches recommended. They are:

• Point-of-Time Conversion: When data is mostly clean, it is possible to map the databases from legacy to new and directly migrate data at a particular time point into the new system tables.
• Lifecycle Mirroring Conversion: When the target system allows backdated transactions and alternate sources of transactions entry, the transactions over the entire lifecycle of the policy or account are extracted from the legacy system, and programming formatted so as to match the new system transaction formats and fed into the new system as backdated transactions. The policy or account is thus built from scratch on the new system.

Typically, owing to existing production support load, these issues are considered a low priority and can remain open for years. Hiring scarce mainframe contractors may not be a cost-effective answer.

NIIT involvement with large legacy clients has enabled it to design a formal methodology for improvement of legacy systems. Given the high cost of legacy infrastructure, these programmes have in many cases given Return on Investment in as little as one year. NIIT's Insight tool framework is used extensively for impact analysis and assessment. The vast bulk of the activities happen from offshore.