What are the Main Legacy Systems Advantages and Disadvantages

5 min readMar 3, 2021

Today, most companies are conflicted about abandoning legacy systems for newer alternatives. Even with new technologies replacing old ones, some agencies still have difficulty adopting the “ in with the new, out with the old “ mantra.

Now legacy systems are relatively widespread across many industries, and most federal agencies are not left out.

A 2019 study carried out by the US Government Accountability Office (GAO) identified 65 legacy systems ranging from 8 to 51 years old, with about ten critically in need of modernization. However, only about seven out of the ten agencies responsible for these legacy systems had documented modernization plans as of 2019.

But with the COVID pandemic, some frailties of legacy systems have been exposed. A well-known example is the case of held-up unemployment stimulus checks because the payment management system was written in COBOL — one of the oldest programming languages.

So, is modernization the answer? What are the pros and cons of legacy systems?

This choice is difficult since many agencies are conflicted between modernizing and sticking to legacy systems.

This article will address the pros and cons of modernizing and maintaining legacy systems, as well as provide guidelines for choosing the best option.

What Is a Legacy System?

The term ‘legacy system’ came into existence in the 1980s to refer to computer systems that set the standard for software in the future. Although this name suggests that the software is ‘out of date,’ a legacy system can still function and solve problems.

According to Gartner, a legacy system refers to a technology based on outdated operating systems but is still reliable for day-to-day operations.

Primary Advantages of Using Legacy Systems

Are there any advantages of using legacy systems in today’s world?

Of course, legacy systems offer several advantages even though they are built on outdated technology. Here are some advantages of legacy systems:

Legacy systems are familiar

Having a legacy system provides a unique feeling of familiarity and comfort. In actuality, this close attachment is among the most common reasons for retaining legacy systems.

The entire workflow is smooth since everyone knows how to access records and use the software. As such, it makes it easier to carry out daily tasks with no hitches whatsoever.

Legacy systems are efficient for specific tasks

Efficiency is another legacy software advantage. Some legacy systems, despite being old and outdated, still work perfectly fine. And most importantly, these systems are typically designed for maximum capacity and remain reliable and durable in most cases.

For example, banking systems use legacy systems and mainframes to facilitate most of their transactions. And although they might be difficult to maintain, they are still efficient in carrying out day-to-day operations.

Legacy systems ensure continuity in business operations

Modernizing software or switching to entirely new technology is a delicate process that could put business operations on hold. Alternatively, maintaining the status quo (legacy systems) lets business operations run smoothly with no hitches or pauses.

Legacy system replacement is painful

Tons of new technologies are currently taking over industries globally. However, switching from a legacy system to an entirely new technology can be a resource-intensive task for any company. And when you acquire new software, you need to hire and train specialists to use it as well as consider all associated risks.

Primary Disadvantages of Using Legacy Systems

Now that we’ve outlined the legacy systems pros, let’s discuss the disadvantages of legacy systems.

Do legacy systems pose any potential risks? What are the legacy systems cons? Let’s find out.

Compatibility issues

Legacy systems may support certain data files and formats at the beginning. However, these standards often evolve beyond what the legacy system can handle after a short time.

Since old software cannot handle modern technological demands, companies would struggle to meet their business goals. Consequently, these businesses would end up losing essential opportunities.

Limited flexibility

Legacy systems usually offer limited flexibility, which makes them challenging to change or customize. As a result, companies struggle to cope with the evolving industry’s rigors, highlighting one of the primary disadvantages of legacy systems flexibility.

On the other hand, modern systems are more flexible and can easily adapt to updates or technological advancements.

Functionality issues

Reduced software functionality is a crucial legacy software disadvantage that companies may face from time to time.

In most cases, the system would be unable to run and integrate certain software programs or carry out specific functions.

A tragic example of the functionality issues posed by legacy systems is the Comair airline company tragedy. Software malfunction cost the company around $20 million and badly damaged its reputation, culminating with the CEO’s firing.

Old interface

Most legacy systems have old interfaces, which is one of the disadvantages of maintaining legacy systems. In today’s world, an outdated interface can hurt any business by derailing customers’ trust in the brand, leading to a decline in sales.

In the same vein, an outdated interface provides a horrible user experience. The displays are difficult to read, and the data is challenging to interpret.

Costly maintenance

The U.S. Federal Government was forced in 2018 to spend nearly 80% of its IT budget on the maintenance of outdated legacy systems. This case highlights the possible financial implications of not modernizing legacy systems. Besides, legacy systems require the expertise of skilled technicians, which is currently in limited supply.

Security vulnerabilities

Legacy systems are prone to malware attacks from bad actors. The absence of software patches and upgrades leaves the legacy system susceptible and defenseless to potent attacks. And eventually, they end up spending extra to support the system while paying for special licenses.

Read the full article on ModLogix

Originally published at https://modlogix.com on March 3, 2021.




ModLogix helps organizations move legacy applications to new secure, stable, and scalable platforms. To explore more, please visit https://modlogix.com/