A legacy system is defined as:
A computer system or application program which is often mainframe based and utilizes older technologies. In many cases these continue to be used because of the cost of replacing or redesigning it, and often despite its poor competitiveness and compatibility with modern equivalents.
These systems have typically been in operation for a long time, and whose functions are too essential to be disrupted by upgrading or integration with another system. In most cases these systems are large, monolithic and difficult to modify.
The facts on legacy systems:
- The challenge faced by many organizations is their legacy systems often do not support direct reporting and analysis from important business information contained in these systems.
- The barriers represented by legacy systems artificially limit the creativity and ability of end users to solve problems and perform the full scope of reporting and analysis on the data that currently exists in their organization.
- The typical solutions that are put forward - upgraded software, data marts or custom programs - all require a significant commitment of time and financial resources, making it difficult to build a strong business case for many projects that involve legacy systems.
- The fall back decision of ‘do nothing’ has consistently proven to have its own real costs, both hidden and visible, as organizations are unable to make decisions and see risks based on all the information that could be made available to them.
