How to migrate legacy systems from mainframe to open systems technology

It is widely acknowledged that it is the legacy systems which are preventing most organisations from moving from mainframe technology to open systems technology. A legacy system tends to be a system which has been run by an organisation for upwards of 10 years and has acquired its name by being handed down. You may not have the original documentation, and it may be difficult to maintain and enhance, but it has probably taken many years to write, is essential to the smooth running of the business. The author discusses how to migrate these legacy systems from mainframe to open system technology. He considers a set of tools from Legacy Software Downsizing Ltd of Manchester, called Powerdrive, to automate the migration of legacy systems to Unix relational database