The Hazards of Legacy Systems
Being the owner of a software system with a dedicated customer base sounds like the kind of position one would like to find themselves in. At least until it gets superseded and you have to face dealing with a legacy system.
Many developers have a strong dislike of legacy systems and consider them problematic for a variety of different reasons.
Reliance on Antiquated Hardware
Software running on antiquated hardware can rapidly become a heavy expense, potentially going so far as to outweigh the cost of replacing both of the software or hardware elements. If some form of emulation or backwards compatibility allows the use of new hardware, this cost can be minimised.
Deterioration of Retained Knowledge
As staff rotate through, it can become increasingly difficult to maintain and expand from a lack of understanding of the system. Staff who were considered experts have retired or moved on. New staff entering the field since the transition to legacy won’t get to experience it in the first place. Documentation will, of course, assist in filling the gaps, but even the most detailed documents will not quite make up for the first-hand experience.
Holes in Security
There are a lot of vulnerabilities that can arise from legacy systems. Older operating systems and applications can suffer from a lack of security patches as support eases. Production configurations of these operating systems can also contribute to security concerns. Both of these factors and more have a hand in putting legacy systems at risk of being compromised.
When New Meets Old
You have to consider the issue of integration. Integrating with other systems is part and parcel of software development, but ensuring successful communication between older and newer technologies can be incredibly difficult.
Fixing Bugs Can Cause More Problems
The biggest concern for many developers is the greatly increased risk of introducing more problems during the process of bug fixing or making enhancements. In many cases, problems will manifest themselves in areas outside of where changes have been made and can be easy to overlook.
As part of our experience as a company, we know first hand just how troublesome having to deal with a legacy system can be. However, we also know that it isn’t impossible as the guide below will demonstrate.
Updating A Legacy System Guide to Avoid Disaster