This firm processes some 70% of all the back office of Wall Street. They have three major systems, for different types of financial instruments and jurisdictions. The three systems are barely integrated. Bringing a client up on any of their systems is a multiyear endeavor. Getting combined reporting from these three systems is nearly impossible.
They have embarked on a major initiative to create a path toward integration, initially integrating the systems they have, ultimately delivering a fully integrated system.
One of the barriers is the complexity of the existing systems. They are massively complex and built on completely different architectures.
One of the systems was designed with an extremely table driven design. While this made it very flexible, it also created performance problems as well as understanding problems. There are only two people in the world who understand all the intricacies of the system.
We built an ontology of the functions that the system covered. We then took all the meta data in the tables that drive the processing and loaded them into a triple store. We constructed a series of sparql queries that allowed relatively new personnel to pose and get answers to complex questions regarding how the existing system works. This has become a key input into their project to understand and integrate their systems to create legacy understanding.