Legacy system: A Simple Definition

Bulb and Programing


After reading this short article, you will better understand what is a legacy system and what are the characteristics and challenges of such a system.

What is a legacy system? A simple definition

A legacy system is a computer based program that is outdated in terms of programming language, platforms, techniques, terminology and/or processes. Most often, when talking about legacy systems, we’re referring to outdated database applications. We are usually talking about software but legacy systems can also refer to antiqued hardware. The antique status of these systems is not necessarily defined by its age. It is more in terms of the discrepancy between the status of what is current and the status of what your system is offering.

For example, let’s say you are using an off-the-shelf software that was created in 1990 but it now has ten new versions since its creation. If the current version is 10.2 and you are working with version 2.5, you have a legacy system. In brief, you are using an old version instead of an available upgraded version. The solution here is quite simple and easy: upgrade.

On the other hand, when you are working with custom and/or in-house made systems, the definition of a legacy system and the solutions at hand aren’t as simple and easy. Read further about the characteristics of a legacy system to better understand what are the challenges associated working with it and ultimately, replacing it.

What are the main characteristics of a legacy system? 4 points to consider

1. Maintenance, integration and compatibility issues

We can declare your system to be considered legacy if you have problems maintaining it and integrating it with other portions of your data management system. The maintenance issues can be due to the outdated nature of the code or processes used to develop your legacy system. Integration to a newer part of your system may just become impossible to accomplish due to compatibility issues. In some businesses, the maintenance, integration and compatibility issues arise when the more competent and experienced IT staff retire. This creates a lack of knowledge in these programming languages and processes. This is usually the death knell for these systems.

2. Security and accessibility issues

The more patching and bridging you have to do to maintain your systems, the more susceptible your system becomes to security breaches and accessibility problems. In terms of security, if your antiqued systems are now connected to the world wide web, this could pose a problem since the web may not have existed when your systems were developed, therefore your systems can’t as easily be protected against attacks. This means adding new layers of code on top of an already crowded system. In terms of accessibility for the end-users, legacy systems can be a bit hard to manage. Using command lines to log into a system is not easy for the average user.

3. Lack of support

Let’s be honest, support is vital to the end-users, especially when you have complicated bridged systems. In the case of off-the-shelf systems, just imagine the nightmare you can end-up with when the vendor no longer support what he sold you. Just imagine how will feel the many businesses still using Windows XP starting April 8. If you visit their website, they’re offering you two solutions: upgrade your current system or buy a new PC.  In the case of custom systems developed by a vendor who is no longer on the market, support becomes complicated and even the accessibility to the code is sometimes impossible. This sure will create issues when the time comes to extract the data.

4. Rampant cost

What is the result of characteristics one, two and three added together? Huge, rampant, uncontrollable cost. This is probably what will convince most businesses to finally agree to let go of their legacy systems and embrace and up-to-date solution. The bottom-line and the ROI always win.

End words

Is the solution always to scrap all legacy systems and start from scratch? Definitely not. There are some good reasons to keep legacy systems and we’ll get to it in a later post. What I consider a legacy system and what you consider to be outdated may just not be the same. Some old exploitation system may work just fine for your business. Taking care of legacy systems is not a decision to be taken lightly.

If you want to learn more about how Kohezion can be a great replacement for your legacy system, watch this video.

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