Introduction to Legacy System
A legacy software system is an old computer system or application program which is still being used only because it is performing a useful job for the community, even though new technologies are available. Legacy software systems are programs that are still well used by the community or have some potential inherent value that was developed years ago using early versions of FORTRAN or other languages. For example, Mainframe runs 64 bit Linux and java alongside 1960s vintage code (which is a legacy software developed in 1960s).
Quality of the Legacy System
Legacy software has been maintained and developed for many years by hundreds of programmers and while many changes have been made to the software, the supporting documentation and programming may not be of current style. These factors lead to highly unbelievable costs in maintaining the legacy software yet, these systems support core business functions and are essential to the business. Thus, there is a need to find ways to make these programs more maintainable without hampering their current usage and also safeguard the information they contain. The solution is to discard the software completely and start again with a new system.
But this may lead to inevitable loss such as:
- The software may actually work well, and its behavior may be well understood. A new replacement system may perform much worse, at least in the early days of replacement. Hence, it may be worth recovering some of the good features of the legacy system.
- Software contains years of accumulated information, which is not represented elsewhere, so discarding the software will also discard this knowledge.
- A typical large legacy software system has many users. It may not be good enough to demand that users undertake a substantial rewrite for no distinct benefit. Therefore, it may be important to maintain the interfaces and exact functionality of the legacy code.
Users may prefer an evolutionary rather than a revolutionary approach to modernizing their software because generating new software will most often introduce new bugs and this would degrade the users’ trust in the software results.
Thus the only way to avoid the above losses is to enhance the legacy software from time to time so that it meets the requirements of the new computing environment. It implements the requirements of new business. It becomes interoperable with more modern systems and databases. It works within a network environment.
Why the Legacy System is Used?
The reasons are varied as to why a company would continue to use legacy systems.
Some of them are as follows:
- Investment: Although maintaining of it is expensive, upgrading to the new technologies systems requires more investment.
- Fear: Adding a sudden change is hard and moving to new technologies or systems can inspire some critical resistance.
- Difficulty: The legacy software may be built with a programming language which makes it hard to find personnel with skills to make the migration. Planning the migration of data from the legacy system and defining the scope of the requirement for the new system is overwhelming.
Problems with Legacy System
Following problems can be caused due to the legacy system.
- Maintenance is costly: The cost of maintaining a legacy system is expensive. Maintenance keeps the works of legacy system softly, but at the same time organization is throwing good money after bad.
- Data is stuck in silos: Data silos are byproducts of the legacy system. Many older systems are designed in a such way that they cannot integrate with each other and many legacy systems software solutions are built on a framework that cannot integrate with other or new systems. In other words, we can say that each legacy System is its own data silos.
- Compliance is much harder: Compliance regulation required companies to know what user data they have, where it is, and who is accessing it. An organization with good user data needs to maintain well-governed d records which are harder to automate.
- Security gets weaker day by day: It does not only leave an organization behind with old technology, but it can also damage the reputation of an organization by putting data at risk of a breach. At some point, the vendor does not support the legacy system or provide a much-needed update, opening legacy systems up to a security risk. Even if the update is available, its installation process can be risky and is postponed for fear of breaking the system. With advanced technologies, the risk for the legal system increases.
In this article, we have seen what is a legacy system and why it is used.
This is a guide to Legacy System. Here we discuss the introduction, quality, use, and problems with legacy system. You may also have a look at the following articles to learn more –