How to approach legacy software modernization

Abto Software
4 min readMay 30, 2023


How to approach legacy software modernization

Digital innovation is rapidly gaining momentum, which means legacy products might quickly become obsolete. Software modernization becomes inevitable if the already implemented legacy systems are no longer efficient, don’t withstand regulatory requirements, or cause other problems.

Refusing transformation, numerous organizations keep their legacy products as long as they remain functional. However, naturally, those companies face challenges associated with day-to-day productivity, which enforce software extension or modernization.

What is legacy software?

A so-called legacy product is an outdated piece of software/hardware meeting primary business requirements. An inefficient legacy system is functional, but causes several problems, typically comprising reputational and financial damage.

Some cases that might fall under this description:

  • A platform with no functional replacement and no security updates
  • A platform with no security patches
  • A piece of software not compliant with the acknowledged standards
  • A piece of software not compatible with the modern systems being utilized

Why update legacy software

Timely approaching software migration and modernization might provide:

  • Improved performance — by implementing modern-day technology, an organization can enhance overall performance and drive greater revenue
  • Enhances security — by taking appropriate measures, a company can address emerging vulnerabilities preventing numerous negative consequences
  • Greater compatibility with technology — legacy solutions are often not compatible with newer operating systems, third-party integrations, and other
  • Ensured compliance with guidelines — legacy solutions might struggle to meet specific standards, causing serious legal risks

Without adopting custom-designed, modern software solutions, you risk:

  • Reputational issues
  • Financial losses
  • Lacking functionality
  • Restricted flexibility and scalability
  • Issues with application compatibility
  • Issues with regulatory compliance, and more

Modernization approaches explained briefly

There are three most-applied modernization strategies, which comprise rehosting, rewriting, and rebuilding. Other existing modernization methods also include encapsulation, replatforming, refactoring, re-architecturing, and replacement.

The strategies mentioned above are differentiated by purpose, investment affordability, and implementation. For example, if we compare rehosting with other popular methods, it is the cheapest, but can be successful only when the to-be-modernized legacy application is consistent.

Once again, the common modernization approaches are the following eight:

  • Rehosting — moving to another environment without making significant modifications
  • Rewriting — writing everything from scratch while retaining the functionality and specifications
  • Rebuilding — similar to the previous modernization approach, creating a newer version but introducing new features and better user experience
  • Encapsulation — wrapping the existing components within the new environment
  • Replatforming — migrating to another platform
  • Refactoring — restructuring the existing codebase
  • Re-architecturing — redesigning the software’s architecture
  • Replacement — replacing the software completely with another software solution that meets determined requirements

When comparing modernization options, one should always consider:

  • Business objectives and goals — for example, when approaching legacy RPA platform modernization, what are the strategic business objectives and goals an organization is striving to achieve?
  • Technical feasibility and compatibility — for example, if starting legacy medical portal modernization, what are the required technical skills and resources to undertake the project?
  • Available budget
  • Project timelines
  • The impact on workflows
  • The availability of resources
  • Scalability requirements
  • Regulatory compliance

Modernization stages: Step-by-step guide

Legacy software evaluation

The organization must assess the state of the legacy software to identify its strengths and weaknesses.

Business goal identification

The company must define desired outcomes (improved performance, enhanced security, and others).

Scope determination

The team then establishes the boundaries and extent of the prospective project, including constraints.

Strategy determination

At the next stage, the team can choose the appropriate modernization approach for the prospective project considering factors such as business objectives and goals, and else.

Choosing the right partner

Next step — choosing the right partner based on:

  • Technical skills — choose vendors who can smoothly handle software modernization
  • Domain-specific experience — contract providers that have relevant experience, for example, healthcare-focused companies should go for partners who deliver healthcare products

Testing and quality assurance

Don’t skip quality assurance if you value reliability.

Product deployment and rollout

Next, the modernized software is deployed into the production environment, ensuring a smooth transition from the legacy solution to the updated system.

Ongoing maintenance and support

Lastly, the modernized software should be thoroughly maintained and supported — don’t underestimate continuous improvement, bug fixes, updates, patches, and monitoring.

Summing up

In today’s dynamically evolving business landscape, legacy modernization has become practically inevitable. Moving towards business digitalization, in particular legacy modernization, mitigates various serious issues, including low competitive ability, reputational and financial damage, and more.

By changing your strategy, you can benefit from:

  • Competitive advantage
  • Smarter resource-allocation
  • Better performance and efficiency
  • Ensured security
  • Improved agility and flexibility
  • Future scalability
  • Application compatibility
  • Regulatory compliance, among other business benefits



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