The process of migrating legacy applications to modern platforms is a challenging and fraught one. As businesses strive to take advantage of new technologies like cloud computing, mobile apps and modern approach to development, they frequently need to begin with updating aging software systems. But these legacy migration projects also have unique challenges across areas such as budgets, personnel, technologies, and processes.
Before delving into specific migration challenges, it’s helpful to level-set on what constitutes a legacy application. There are a few key characteristics:
With this backdrop in mind, tackling a legacy migration requires strategic planning combined with flawless execution. The following sections outline the most prominent challenges.
For many organizations, the #1 barrier to beginning a legacy application migration is budgeting properly for the large effort required. Unlike building new software from scratch, updating and transitioning aging systems needs ample time and resources. Specific factors contributing to the significant budget requirements include:
Multi-Year Timelines. Real-world migrations are multi-phase projects spanning 2+ years in many cases. Attempting too much too quickly heightens risk levels.
Labor Costs. Legacy platforms often require specialized skill sets like outdated programming languages. Finding this talent can be expensive.
Transition Expenses. Maintaining existing apps during migration has duplicate labor/hosting costs versus decommissioning right away.
Unforeseen Complexity. No matter how thorough planning aims to be, unexpected obstacles in tangled legacy code will surface frequently.
User Training. Preparing employees for changes in business processes, software UX, reporting, and more also pulls key staff away from daily productivity.
Conservative budget estimates for even small legacy migrations often land between 500,000 and 1 million. Executives must account for the lengthy timeline and wide spectrum of costs across technology, process, and personnel changes.
The most valuable information regarding how legacy applications function lies in the minds of engineers, developers, and IT staff who have worked closely with the systems for years. However, these personnel resources present their own challenges:
Missing Documentation. Unlike modern software projects, legacy app documentation is frequently sparse or non-existent. Tribal knowledge fills these gaps but isn’t easy to capture.
Lack of Visibility. With no supporting documentation, it’s nearly impossible to inventory all legacy application components, data schemas, dependencies, and interfaces.
Retirements and Turnover. Veteran IT professionals with the deepest legacy insights often retire or leave before migrations conclude.
Proactive mitigation steps for knowledge loss threats include focused interviewing, code analysis automation, and job shadowing.
The very nature of legacy platforms also introduces numerous technical obstacles during migration programs. Decades of patched updates create layers of complexity, gaps in performance monitoring, and other issues commonly referred to as “technical debt.”
Common examples include:
Programming Language Barriers. Legacy languages like COBOL and FORTRAN require niche modernization skills that are not broadly available in today’s software talent pools.
Performance and Scalability Limits. Outdated processing and storage infrastructure often can’t handle today’s transaction volumes and data growth.
Integration Shortcomings. Inflexible, tightly coupled legacy interfaces struggle to blend modern platforms into processes.
Security and Compliance Deficiencies. Antiquated systems weren’t designed to meet contemporary regulatory demands around privacy, access controls, etc.
While re-architecting aging platforms can radically improve technical debt issues, most organizations phase these types of invasive changes gradually to limit disruption.
An overall execution strategy with stakeholder alignment also proves challenging based on the range of migration complexities. Two common high-level approaches each have tradeoffs:
It favors a ground up rebuild of legacy application architectures before even contemplating modernizing underlying platforms and infrastructure components. The benefits are greater flexibility to make more radical changes but at the cost of much higher risk, cost and effort.
The second approach is to migrate the technical platforms of the legacy platforms to the modern platforms before any material architectural changes. It reduces initial risk, but limits future architecture optimization.
This spectrum of potential strategies within these two endpoints lies between cost, risk, and business impact. However, it can be difficult, but necessary to align executives, IT leadership and other stakeholders on the right path.
Legacy modernization also requires specialized tooling that can interrogate programming languages, automatically convert codebases, improve performance, allow interoperability, and more. With providers all offering robust suites, tool selection itself has key challenges, such as:
Thoughtfully evaluating tools against current and future needs, capabilities, and constraints is vital for legacy modernization success.
Since legacy applications often directly impact customer-facing processes, user interfaces, business reporting, and more, migrations require extensive end-user preparation. Failure to implement comprehensive change management jeopardizes user adoption of modernized solutions. Tactical elements of strong adoption programs incorporate:
Early Involvement. Giving user representatives a voice in migration plans tailors changes to actual needs while managing expectations.
Multi-Modal Training. Combining classroom training, online content, job aids, sandboxes, and other formats accelerates learning.
Performance Support. Embedding assistance tools, help menus, and knowledge base search directly inside new UIs assists during and after deployment.
Power User Networks. Identifying power users across the organization provides credible voices that influence peers to embrace changes.
Post Go-Live Reinforcement. Continuing education, feedback channels, and optimization after launch speeds full productivity restoration.
Earning end-user buy-in directly correlates to migration success but requires significant upfront and ongoing communications.
With multi-year time frames filled with hurdles, legacy migration programs almost inevitably face delays or cost escalations. The fundamental project management challenge centers on maintaining control via tools like:
Phased Rollouts. Transitioning functionality, users, or business units incrementally limits risk exposure at any given time.
Value Tracking. Regularly demonstrating incremental business value realized justifies continual investment to executives.
Staff Augmentation Plans. Having contingent staffing contracts in place allows rapid team expansions when unforeseen issues surface.
Automated Testing. Scripted regression testing reduces quality assurance timelines during complex cutover events.
Executive Steering Committees. Involving leadership in key milestone reviews maintains alignment on progress and priorities.
While overruns plague even the most meticulously planned migrations, mitigations that blend human governance and technology automation provide control mechanisms when the need for additional time or budget arises.
Legacy modernization projects enable enormous progress – replacing aging systems with agile, resilient, scalable digital platforms. But organizations cannot underestimate the multi-dimensional challenges inherent in these migrations. From costs and technical debt to change management and staffing, proactive planning is mandatory, as is thoughtful sequencing of incremental changes to balance uninterruption of current operations.
If initiating a legacy app migration journey, ensure executive leaders endorse sufficient budgets for multi-year efforts. Conduct audits to detail all legacy components and dependencies. Build cross-discipline teams drawing both internal and external expertise, supported by advanced software tools. Develop staged rollout plans prioritizing elements by business criticality. And overcommunicate changes to ensure organizational alignment and user adoption.
