The pace of technological innovation is faster than ever, with new frameworks, languages, and infrastructure emerging constantly. For many companies, this means their existing “legacy” systems can start to feel outdated and inflexible in comparison. Migrating these legacy systems to modern platforms is, therefore, a strategic priority for most enterprises today.
However, transitioning business-critical applications from legacy environments also poses some major challenges. Re-platforming initiatives are complex, risky, and resource-intensive. Companies can end up falling into common pitfalls that cause budgets to balloon and timelines to slip. Legacy migration projects often fail entirely. Sometimes the risks are too great, so some companies choose an application modernization service for tasks of this kind.
This article outlines a set of best practices and guiding principles IT leaders should adopt when planning and executing a transition from legacy platforms to modern application architectures. We’ll cover establishing the right governance, choosing appropriate migration strategies, optimizing integration, and driving user adoption of new systems.
Follow these recommendations, and your organization will be able to retire legacy environments smoothly in favor of modern applications, minimizing disruption to the business.
Build a Strong Governance Foundation
The first step in any legacy migration initiative should be establishing robust program governance. This starts with securing executive sponsorship and aligning business and IT leaders on the scope, objectives, costs and timelines involved.
It’s critical to articulate the pressing business needs that are driving the migration so stakeholders understand the rationale behind the significant time and budget investments required. Quantify the expected ROI in terms of increased agility, lower TCO, improved customer experiences and more.
A steering committee should be created with representatives across departments to provide guidance and oversight throughout the transition. Committee members need to evaluate migration readiness, monitor progress, coordinate resources, and help remove roadblocks.
The program manager in charge should institute a formal change management process as well. Any alterations to the plan – whether in terms of schedule, budget or requirements – need careful analysis and sign-off from steering committee members and sponsors.
Choose the Optimal Migration Strategy
Once governance is in place, the next key decision is which migration strategy (or combination of strategies) makes the most sense for transitioning legacy applications over to modern platforms. According to Forbes, 70% of organizations are currently undertaking some form of legacy modernization effort. Each approach involves different tradeoffs that must be weighed:
Rehosting (Lift and Shift)
Also known as “lift and shift”, this fastest and least expensive migration option involves taking an application as-is and redeploying it on modern infrastructure without changes. Using automated tools, legacy apps are “lifted” then “shifted” or rehosted on new platforms, typically IaaS in the public cloud. This route allows enterprises to realize cost savings and flexibility benefits of the cloud quickly without disrupting current operations. Code and functionality stay the same, so risk is low. However, the potential capabilities of the modern platform go unrealized. Technical debt and architectural constraints remain unaddressed, which can cause long-term challenges.
Replatforming (Lift, Tinker and Shift)
With replatforming, applications are modified to some degree before being migrated over to new environments. This usually entails rearchitecting legacy apps to take advantage of modern platform services and capabilities while preserving codebases as much as possible. Companies can achieve improved scalability, performance and operational efficiency without the risks and costs of a ground-up rewrite. However, some legacy constraints remain, and integration challenges are likely.
Refactoring / Re-architecting
A deeper level of code change is undertaken here to optimize applications, remove deprecated features and upgrade UX/UI design. Some components may be redesigned as cloud-native microservices. This approach enables more substantial technical improvements but is more disruptive. While existing business logic can be retained and restructured, application functionality and performance get a notable boost. However, budgets and timelines must account for the required reengineering efforts.
Rebuilding (Rip and Replace)
As the name suggests, rebuilding involves fully discarding legacy application code, data structures and architecture, replacing it with brand-new modern alternatives developed from scratch. This allows for the most innovation and customization but is the most expensive and risky migration path. However, for legacy apps near the end of their useful lifecycle, a rewrite in new technology can be the smartest long-term play despite short-term disruptions.
The best strategy depends on an app’s business criticality, lifecycle stage, complexity and integration touchpoints. In most cases, enterprises use a combination of the above. Conduct thorough application assessments and take a portfolio approach – some systems may be re-platformed, others rehosted, and a select few rebuilt entirely.
Accelerate Transition Timelines
Transforming business systems can be a multi-year endeavor. To accelerate legacy migrations, leverage automated tools and cloud services as much as possible. Here are a few examples:
- Cloud-readiness assessments rapidly evaluate legacy application portfolios for replatforming
- Code conversion tools transplant legacy codebases to modern languages
- API gateways/integration platform services streamline connecting old and new
- Cloud infrastructure minimizes the need to procure and provision new data centers
- Containers and orchestrators enable easier app deployment/management
- CI/CD pipelining processes automate testing and releases
The right automation and cloud technologies save considerable development and operations efforts. They also allow IT teams to take an iterative approach – moving legacy apps to production faster than continuously improving.
Carefully Evaluate and Integrate Dependencies
Legacy environments often have deep, nested dependencies. Before decommissioning any legacy system, all its upstream and downstream application connections must be mapped out and accounted for.
Start by creating a visual diagram noting all endpoints the legacy app touches. Determine whether each connected system is being replaced, retired, or remains mandatory. Then, the level of effort entailed in modifying touchpoints during the transition will be assessed.
Some integration challenges commonly encountered when migrating legacy platforms include:
- Hardcoded links between legacy apps need redirecting to new endpoints
- Shared databases may need migration, replication or partitioning to supply data to both old and new systems
- Transaction processing may require coordination across legacy and modern platforms
- End-user interfaces into legacy apps need updating with links to new applications
Factor in the above integration considerations during migration planning to avoid unexpected costs or timeline delays down the road.
Take an Iterative, User-Focused Approach
For a migration from legacy platforms, use an iterative process that revolves around user needs while migrating to a clean platform. Rather than a single, high-risk “big bang” go-live, take an incremental rollout approach.
Deploy the modernized version of the application to production in a minimally viable way first. Once the essential user scenarios are rebuilt and you’re operating, think about what gets the least built (somewhat erroneously termed legacy functionality) and put that on hold for a time.
Solicit end-user feedback on the new application right away. Then, functionality will be continuously enriched in subsequent releases until all required capabilities from the legacy system are fully replaced.
The new application is delivered more quickly with actual business value due to this agile, user-driven methodology, which eases the adoption curve for employees. Iteratively, the modernized platform also provides support teams with operational experience so that they can gradually scale up the technical support capabilities without being overwhelmed by a ‘big bang’ rollout.
Provide Comprehensive User Training
To further ease the transition process for end users, provide comprehensive training and support programs that include:
- Interactive online learning modules employees can reference on-demand
- Instructor-led virtual or in-person training sessions and workshops
- Online quick start guides & FAQs with screenshots and video
- Chatbots or virtual assistants to respond to common user queries
- Expanded help desk capacity during the migration period
Use the above best practices to set users up for success. The more effectively employees can leverage the new systems from day one, the faster your organization realizes ROI on legacy migration efforts.
Carefully Decommission Retired Systems
Once validated as no longer in use, legacy platforms should be fully decommissioned using these steps:
- Confirm no remaining application dependencies or users’ first
- Archive legacy data as per regulatory requirements
- Unplug access credentials and logins; revoke system authentications
- Shut down legacy hardware infrastructure and software licenses
- Delete inactive user accounts and access controls
- Wipe legacy application data from disks/storage volumes
Following secure deletion protocols is essential for the governed, compliant retirement of outdated technology.
Define Clear Rollback Contingencies
Even with the best efforts, there are still unforeseen issues that can occur after launching modernized systems. In the event of an emergency, migration teams should define contingency procedures to roll back to legacy platforms smoothly.
Set up fallback criteria such as unacceptable system downtime or data corruption. Determine who is authorized and will execute rollback plans. Processes to revert to legacy infrastructure and restart retired applications should be documented in step-by-step runbooks that can be run until contingencies are resolved.
By proactively planning for rollback, IT teams can minimize business disruption even if major technical problems emerge. Keep contingency plans in place until modern application stability is proven over time.
Conclusion
It facilitates enterprises in innovating faster and responding to the changing market demands of moving a legacy IT system to modernized applications. But getting these benefits realizes also upon methodical planning including mitigating the risk involved when the workload to be transitioned is business-critical.
Following the tips described in this guide on creating a secure, robust and effective governance either for replicating previous processes on a new or older platform or for creating new processes on a new platform, you will position your organization to inherit previous legacy platforms and replace them with next generation architecture. Although it’s a difficult assignment, if you approach it with the right strategy and by adhering to the rigor, your new modernized applications will begin providing impact.
