Legacy Systems

In many organisations, key information systems have been in place for many years. These systems often run core business processes such as billing and logistics. Such systems are known as legacy systems and have a number of properties. They are usually based on old technology, perhaps using mainframe languages such as COBOL. Their documentation is weak, if lost. Nobody really knows how they work, and nobody is prepared to attempt to change the system. While the technology is old, the system works well and acts as an engine for key business processes. Replacing it would be prohibitively expensive, so it tends to get left alone. This makes things very difficult if we want to connect it to a new system or provide a data feed to a new system. Means need to be found to replace legacy systems. This may involve enclosing it in a new interface and gradually removing and replacing parts of the legacy system. But legacy systems are also a source of rich data and can have new purpose, as demonstrated in the case of the Uruguayan Perinatal Care Information System.

Task

Question 1. Define and give examples of legacy systems in organisations.Explain why they are important. Outline the problems with them. How can legacy systems freeze organisational structure and inhibit changes in business process?Give a case study of the problematical effect of a legacy system.Survey the solutions to legacy systems. How can they be replaced?

Question 2. Today's legacy systems are the large mainframe transaction systems. Will there be new legacy systems in 10 years' time? Will they have the same problems?What are the good things about legacy systems?