The document discusses legacy systems, defining them as outdated technology that, despite their obsolescence, is still utilized by many organizations due to reliability, customization, and established functionality. It explains reasons for their continued usage, including resistance to change, high cost of maintenance for modern alternatives, and the risk of unknowns with new systems. Notable examples are provided, such as NASA's space shuttle program and various banking and military applications that still rely on legacy software.

1. A Beginners Guide To Legacy Systems
Blog URL: https://www.goodcore.co.uk/blog/legacy-systems/

2. We all have dealt with slow systems at least once in our lives, either
at our homes, at our universities or work. We all have gone through
the phase when our computers got stuck in the middle of an
important task or our favorite application hung and the only option
left was to restart it.
Have you ever wondered why this happened or still happens? Well,
if you did and couldn’t find your answer or are generally interested
to know, you are at the right place!
Through this article, we will try to solve this mystery as we first
explore what is a legacy system. We will also look at its drawbacks
and discuss why they are still in use. And lastly, we will look at some
examples of legacy technology. We assure you that this will be an
interesting read for you.
So let’s get started!

3. What Is A Legacy System?
A legacy system is an obsolete computer system, programming language, software
application, process or technology that can no longer be maintained, replaced or easily
updated. It certainly does not mean that the legacy system is not in good working
condition. Many organisations or companies still find these systems essential to their
daily work. Though, it depends upon the individual or the organisation to either upgrade
or replace it.

4. According to the definition of legacy systems mentioned above, legacy system is a very broad term
and can be applied to many systems out there. In this article, our focus will be limited to legacy
software only.
So, how to tell if the software is a legacy software or not?
Usually, a software is considered a legacy software when it is older than ten years. The following
factors contribute to determining a system as a legacy:
• The system no longer supports the multiple software that an organisation or company requires
• The skills required to support the system are no longer available in the market or, in other words,
have become obsolete
• The cost for maintenance of the legacy software is usually high as compared to that of modern
software
• The performance becomes slower
• It cannot be extended or upgraded
• It takes longer than usual for maintenance
• It is unable to handle a large number of users
But to our surprise, these systems despite being unreliable are still widely used by many
organizations.

5. Why Are Legacy Systems Still Used?
Believe it or not, many organizations and/or businesses still use legacy technology even when they
can choose to migrate to the latest technology. But the important question is why do they still use it?
There is this famous saying, “If it ain’t broke, don’t fix it.” Hence, legacy systems are still used
because they get the work done. Most of the legacy systems are so old that no one knows on what
specifications do they work. Therefore, many organisations either do not bother to disturb the
process or prefer not to introduce a new technology altogether.
So whenever you see software or a system still in use despite it being old, do not judge the
organisation or the company right away. But do think about the uses which we have listed below:

6. Change Is Not Good
As we briefly discussed above, many organisations do not prefer change. Hence, they barely switch
to new systems. Also, changing their systems means providing training to the users, which might cost
them both time and money. Moreover, chances are that the users might resist change. Therefore,
many organizations resort to legacy technology as long as it serves their current needs.
For example, Windows XP was first introduced in 2001 and was widely used by a lot of users globally.
In 2014, Microsoft ended its support for Windows XP and launched newer versions of it. However,
Windows XP is still used, if not widely. The main reason is that the users cannot afford to upgrade
their systems or are not ready for change.

7. Tailor-Made Software
Most of the legacy software is customized according to the organization's needs at the time of
development. The software is developed with an aim to function for a longer period, without having
to make major changes.
Since organizations customize their software, which eventually becomes part of legacy technology,
therefore it can provide the organization with a competitive advantage over others. Hence, we still
see the software functioning well even after 6-7 years. Of course, they need timely maintenance.

8. Bridging Older Technology With The Newer Ones
Legacy systems are still in use because there are different types of software available that bridge the
gap between older technologies with the newer ones.
They do so by providing a framework on which newer versions are developed to continue the legacy
of older technology which might not exist but act as a precedent.

9. Reliable
When we talk about change, we also implicitly refer to the reliability aspect. For many organizations,
the durability and reliability of software or a system are of utmost importance. Because they have
been using the software for a while, which has now become a legacy. They are afraid to test out a
new system or software because they are skeptical of the new technology not working as robustly as
their old legacy software did.
With the legacy software, they already know how to handle it and hence there is predictability to
how the software will react in different circumstances. Most importantly, they feel at ease when
using a well-known software or system rather than familiarizing themselves with the new one.

10. What Is An Example Of A Legacy System?
So far, we have understood what legacy technology is, but to make it easy for you, let us explain it through an
interesting example.
You must have heard about NASA’s Space Shuttle program, which was an Earth-to-orbit spaceflight. Initiated in
1972, through Space Shuttles, NASA used to transport cargo and crew members to the International Space Station.
The program was based on multiple legacy software but mainly on Flight Analysis and Design System (FADS).
NASA’s Space Shuttle Program was developed with an aim of 10 years of operational life. Even though the program
retired in 2010, it worked on the same software during those 10 years rather than upgrading to the newer one.

11. According to research on the use of legacy systems in space exploration, legacy software can only be reused if an
organization is capable of the following, which increases the reliability and quality of the software:
• Verification
• Validation
• Testing
• Operational history
These must be incorporated in SDLC phases such as
• Development
• Implementation
• Usage
• Maintenance
Here are a few additional examples of legacy software that you might be interested to know about:
• The traffic signals that we follow are still based on legacy technology.
• US Military, Britain’s Atomic Weapons Establishment and Airbus still use DEC manufactured PDP minicomputers
which were developed in the 1970s.
• Banks still function on legacy technology. Whenever you transfer your money, the transaction happens through
a legacy platform.
• COBOL programming language is still used in many software even though it is an outdated language.
• Worldwide, sales terminals at various marts still use Intel 286 computers because the software might not work
in advance computers.

12. Let’s Have A Recap!
To summarize what legacy technology is, it is an outdated technology, which
does not support the modern-day needs of the businesses or organizations. Why
do some people still depend on these systems? Because they are accustomed to
it and hardly will ever switch to the latest option.
It is entirely up to you whether you opt to keep using legacy technology or not.
This decision depends on your requirements. We cannot completely rule them
out since they are still useful in many ways such as being reliable, cost-effective,
customizable and most importantly, they get your work done! Yet, we cannot
also deny the fact that these do not meet the modern-day requirements.
Let us know what is your take on legacy technology and this entire debate of
keeping them or not. Leave your comments or reach out to us via email. We will
be glad to know your thoughts on this crucial debate.

13. End.