10 Tried-and-True Steps to Update Legacy Apps

Applications developed in old languages, frameworks, and infrastructure can be a major disadvantage for today’s businesses and organisations. The ability to move these applications to newer platforms opens up new opportunities, better reliability, and cost efficiency. These are the 10 key steps that need to be taken in order to successfully modernize legacy systems.

1. Create a Detailed Inventory

The first step is to identify and comprehensively document all the aspects of your legacy. Record all the applications, interfaces, databases, and support structures that are in place. Organisations can seek assistance from leading development teams such as ModLogix to address this. Capture details on: 

• Functionality and business processes supported
• Underpinning technology stacks
• Interdependencies with other systems
• Usage stats and criticality to operations
• Ownership, maintenance, and age

This inventory serves as a guide of the modernisation program.

2. Build a Strong Business Case

It is impossible to achieve top management support and funding without presenting a strong case for the modernisation of the legacy system. Quantify the tangible benefits across key areas like: 

Innovation Enablement: Modern platforms offer the availability of new technologies such as AI, IoT, cloud, and others. This leads to new products, customer experience and revenue streams. 

Risk Reduction: Legacy systems are also the biggest continuity threats as they are based on scarce skills and obsolete hardware/software. 

Cost Savings: Thus, the maintenance and enhancement costs are minimised through technology sharing and the availability of proper cloud infrastructure. 

Productivity Gains: New systems allow for quicker deployment of new enhancements and the elimination of reported issues. 

Future-proofing: Contemporary architectures are made in a way to incorporate technologies that are yet to be developed.

3. Prioritise Based on Business Value

Smart sequencing is essential, and once executive sponsorship has been obtained, the next steps must be planned accordingly. Categorise group legacy systems into priority tranches by factors such as business criticality or costs and risks.

The strategy of capturing quick wins involves starting by upgrading the least complex systems or the ones that require attention the most. This creates a rhythm before getting into the more important and intricate mission-critical systems. Maintain flexibility – change priorities as the business environment evolves.

4. Select Target Architectures

Subsequently, specify the correct target architectures to which the legacy platforms need to be migrated. Activities such as evaluating the current versus new functionality, data, integration, and compliance requirements should be considered when choosing the future technology architecture.

Typical modernisation targets include migrating legacy systems to: 

• Cloud-native microservices architectures
• Low-code application development platforms
• Container and Kubernetes platforms
• Cloud-based data platforms and analytics engines

Avoid a one-size-fits-all approach - tailor target architectures to each legacy system environment and goals.

5. Execute Detailed Assessments

Conducting detailed assessments of legacy systems prepares for the nuts and bolts of the migration effort itself. Key assessment areas include: 

• Code Quality: Identify areas needing remediation like complex code suitable for refactoring into cleaner modular components.
  
  
• Data Mapping: Catalog all existing data structures and map to new database/schema designs.
  
  
• Integration Points: Document all touchpoints with other systems requiring coordination.
  
  
• Migration Tools: Determine optimal conversion, re-platforming, and re-coding tools for each legacy platform.
  
  

6. Validate Migration Approach

Based on detailed assessments, define the processes, stages, and tools needed to migrate each legacy application to its target platform. Typical strategies include: 

• Re-platforming: “Lift-and-shift” existing application to new infrastructure
• Re-architecting: Rearchitect application to fit new paradigms like cloud microservices
• Rebuilding: Major rewrite of the whole application aligned to the new tech stack
• Retiring: Decommission system and consolidate its functions elsewhere
• Retaining: Keep system as-is if modernisation is infeasible

Validate the right approach for each system through proof-of-concept testing.  

7. Execute Migration Factory Setup

To industrialise migrations, set up migration “factories” - teams with specialised expertise in transitioning legacy systems over to target architectures.

Leverage proven patterns and code libraries to accelerate migrations. Automate processes using CI/CD pipelines for testing, security checks, deployments, and more. Architect for continual improvement to optimise costs and speed. 

Nearly half of the respondents cited cost savings, improved integration with contemporary technologies, and enhanced agility and flexibility as the primary motivators for updating their legacy data and applications in 2023.

8. Migrate Applications Gradually

With the migration factory created, start migrating applications in order of priority. It is advised to take an iterative approach – start with presentation layer migration, followed by the business logic layer, and finally the data. 

Gradual migration is less risky as it allows the old and new environments to exist side by side during the migration process. Employ conversion tables to map old platforms to new ones.

9. Perform Incremental Modernisation

Where full modernisation is constrained by time/budget, perform incremental modernisation of targeted pain points in legacy platforms: 

• UI/UX refresh - Improve user experience without altering back-end code
• Integration upgrade - Expose APIs for interconnecting with modern apps
• Scaling upgrade - Expand infrastructure capacity constraints
• Data optimization - Offload only the database onto modern data platforms

This delivers tangible quick wins before pursuing bigger modernisation initiatives.

10. Leverage Modernisation Partners

Given aging in-house skills, specialised partners can provide invaluable expertise and bandwidth augmentation for successful modernisation: 

1. Migration specialists - Tools, reusable frameworks, and proven factory model for accelerated migration
2. Platform experts - Skills for building, running, and optimizing modern cloud-native architectures
3. Data engineers - Next-generation data platform implementation skills for analytics-driven systems
4. Change managers – Proven ways for gaining user adoption of new systems

Taking a phased approach while tapping targeted external expertise smooths legacy modernisation journeys.

Final Word

The modernisation of legacy systems enables organisations to leverage innovation and reduce technology risk implications. To make sure that your modernisation programmes meet the goal of digital transformation, follow these 10 guidelines grounded in the latest research – from creating business cases to engaging specialised partners.

Prioritise the system based on business needs, undertake the migration in phases, and use cloud-native architecture as future-proof strategy for legacy system replacement.