In many business realities, legacy software still plays a strategic role. At the same time, however, it poses obsolescence problems, resulting in high infrastructure maintenance costs, especially when compared to modern cloud-based application solutions. Today, therefore, the modernization of legacy software takes on vital importance.
What is legacy software
In computer science, when we talk about legacy software, a legacy application or system, we mean all that enterprise software (management, ERP, CRM, SCM, BI) that an organization has invested in for years. Installed and maintained on servers or mainframes in the enterprise data center, legacy software is in many cases still fully functional and essential for manning core processes. However, it has the drawback of being obsolete, and may no longer be compatible with several of the latest technologies currently used. This is because it has generally been developed with outdated programming languages, or because it is characterized by a monolithic architecture: it therefore proves difficult to manage, modify, and maintain, in accordance with modern operating standards and requirements. For IT staff, legacy software becomes complicated to administer, for example, because it may be incompatible with the new version of the operating system you want to install, or because the vendor software has officially ended its support period for that product and no longer provides updates or security patches.
Legacy software, why modernize it
There can be several reasons why a company needs to maintain legacy software: one of these is the fact that it can be verticalized software for a particular industrial sector, equipped with specialized features, and developed to meet specific business requirements, including safety and compliance with industry regulations. The challenge is therefore to evolve this legacy software, through techniques that allow it to be improved in various aspects. These include the maintainability of the software itself, as well as its ability to integrate new features to meet current business requirements.
Business requirements
Today, software, on the one hand, must be upgradeable quickly and frequently; on the other, it must provide scalability and performance levels appropriate to the data demands generated by modern omnichannel applications. To interact with their favorite brands, consumers use a wide variety of channels, such as mobile apps, the web, chats, or social channels. And all these interactions, being able to take place 24 hours a day, through platforms open to a global market, produce volumes of traffic that legacy software has not been designed to adequately manage. So let us see what steps it is advisable to follow in a modernization initiative.
1-Understanding that it’s not just about modernizing software
The first step, before starting any legacy software modernization project, is to become aware that technologically ‘rejuvenating’ software isn’t enough unless organizational processes and people’s way of working are transformed; and unless a change management strategy is also planned that allows this transformation to occur with as little disruption as possible to the daily operations of the company and its internal staff.
2-Evaluate the criticality of working legacy software
When it comes to deciding what needs to be modernized, it’s helpful to have as clear an overview as possible of existing legacy software and the critical processes it controls in the company. Only in this way is it possible to evaluate, given the technical debt of each application, whether it is really worth updating it, by virtue of the benefits it will be able to provide once enhanced
3-Legacy Software: Changing Architecture Can Be Cost-Effective
Monolithic architecture is an element that typically characterizes legacy software. In this architecture, all program components (business logic, database, interface) are interdependent and integrated into a single block of code. Every change on one component is complex, because it affects the others as well. Additionally, legacy software with a monolithic architecture also has scalability issues. From this perspective, moving to a microservices-based architecture can help solve both drawbacks.
4-Migration to the cloud
Thanks to its distinctive properties, the cloud allows it to address many scalability and performance issues in IT resource delivery. However, even when you decide to migrate legacy software to the cloud, you always have to choose the most advantageous solution, which is not necessarily the one that initially presents itself as the least expensive in terms of effort and development costs. For example, the rehosting technique allows you to move monolithic legacy software to the cloud without making any changes to it, but this migration method does not allow you to fully exploit the scalability and reliability benefits that the cloud provides when an application is structured on microservices.
On the other hand, a technique like refactoring, which involves a partial or total redesign of legacy software and allows it to be broken down, even progressively, into microservices, is certainly more expensive than rehosting, but it allows you to fully benefit from all the advantages of the cloud-native paradigm.