So, what is a legacy system? In Healthcare IT, we’re referring to any given older clinical technology system that could be considered for replacement by newer technology, usually because it does not meet the needs of the organization. In a hospital, we may have a homegrown software product that has been in place for many years, and does not send data to other systems, or may require software patches or workarounds just to keep it limping along. When a project team meets, they may say something like “We need to replace our legacy registration system with something that interfaces to the rest of our organization”. In one hospital where I used to work, we replaced dozens of applications with a cross-enterprise system from Epic. In our case, that involved replacing many software modules from McKesson, including the STAR registration system.
In some organizations, a legacy system is defined by the obsolete operating system or hardware platform that it runs on. Whereas many systems these days run on either Linux, Unix, or Windows; some applications may run on a mainframe or Tandem hardware platform, placing it into the legacy category.
Another category of legacy systems may have to do with programming languages. The technology community as a whole has come to expect products to be developed using either open source or industry standard programming languages. Examples are Java, Perl, PHP, and .Net.