The advent of digital transformation has accelerated the trend of legacy application modernization. Businesses of all sizes and verticals have built and deployed their enterprise applications on legacy integrated systems like IBM AS400. The AS400 integrated servers are known for maintaining high uptime and stability. These are the factors that have enticed many businesses to utilize the AS400 systems for the development and hosting of their enterprise applications.  

However, there’s no denying that the AS400 systems are built on legacy monolithic architecture. This architecture combines all application components, such as user interface, communication layers, and business logic into a single codebase and hosts them as a unified solution. This interconnection makes it difficult for businesses to isolate and upgrade an app component without impacting other functionalities. The monolithic architecture offers minimal integration support. This minimizes the possibility of integrating modern security and scaling mechanisms with AS400 applications and hinders digital transformation. 

Transforming the AS00 application’s architecture from monolithic to cloud-native or microservices is essential to resolve challenges in upgradation and tool integration. To fulfill this, businesses should embrace the modernization of AS400 applications. 

AS400 Application Modernization - Definition 

The process of AS400 application modernization refers to the re-platforming, refactoring, or reengineering of AS400-hosted enterprise applications. These techniques improve the AS400 application’s compatibility with cloud-native and microservices architecture. By embracing AS400 application modernization, businesses can equip their AS400-powered enterprise apps to meet varying technical and operational requirements without undergoing major replacement processes. 

Why Hire IBM i Experts for AS400 Application Modernization 

AS400 application modernization is a complex initiative. Traditional programming languages like RPG and COBOL are utilized to build the codebases of AS400 applications. This makes it difficult for in-house IT teams to refactor or rebuild the codebase without adequate expertise. Modernization techniques like replatforming necessitate extensive dependency mapping and configurations. By delegating such modernization tasks to internal IT teams, businesses might risk overburdening their workloads and reducing the efficiency of technical infrastructure management. 

Alternatively, businesses can hire dedicated experts from an AS400 modernization services provider. These experts have in-depth expertise in modernization approaches like: 

• Replatforming – Dedicated experts modernize AS400 applications by migrating them to cloud-native or microservices architecture. To accomplish this, AS400 experts leverage automated mapping and migration tools. These tools enable them to map and shift all the dependencies of an AS400 application from monolithic to cloud or microservices architecture. 

• Refactoring – The refactoring approach refers to reprogramming and optimizing the AS400 application codebase. Through this modernization approach, experts transform the monolithic codebase into modular code components without modifying business logic. Such code components are easy to scale and maintain while ensuring compatibility with cloud or microservices architecture. 

• Reengineering – Application reengineering is an extensive modernization approach executed by AS400 modernization services providers. In this approach, modernization experts rebuild user interfaces and modify the data structure of AS400 applications in line with cloud-native architecture requirements. This enables easy integration of tools and advanced functionalities in AS400 applications and boosts user experience. 
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The Different AS400 Application Layers Modernized by IBM i Experts   

1. User Interface 

The traditional green screen interface of AS400 enterprise applications makes it difficult for teams and the workforce to manage processes more clearly. Dedicated AS400 modernization experts re-engineer the user interfaces of AS400 enterprise applications and improve overall usability. By leveraging IBM’s host access transformation tool, experts redesign interfaces for AS400 applications. This tool enables AS400 experts to write custom UI design scripts in JavaScript and HTML and modify the interface of applications without affecting the backend services. 

After the redesign phase, modernization experts deploy the new interface in the cloud, mobile, and web environments. This deployment enables business teams and the workforce to access AS400 enterprise application services from any location without disruptions. The redesigned interfaces of AS400 applications facilitate smooth navigation for users and improve user engagement. 

2. Database 

Dedicated IBM application modernization services providers migrate the database of an AS400 application to a cloud database. First, IBM experts assess and map all the crucial file structures in the AS400 application’s database. This evaluation enables them to determine the appropriate transformations required for datasets in the AS400 application database. By leveraging ETL pipelines, AS400 experts migrate the database to a staging environment. 

With the help of data profiling tools, AS400 experts transform and standardize the data structure of the AS400 application database. After standardization, experts move the database from a staging environment to a cloud database environment. This migration enables modernization experts to incorporate access controls and encryption mechanisms on the AS400 application database and protect datasets against breaches and losses. 

3. Codebase 

The IBM i application modernization experts modernize the codebases of AS400 enterprise applications to facilitate incremental updates and functionality improvements. Through extensive code auditing, IBM i experts identify and remove the redundant program files and loops in the AS400 application codebase. To improve the modularity of the AS400 application codebase, IBM i experts refactor the code. This involves transforming the old RPG III or COBOL scripts into free-form RPG code modules. Modern cloud and microservices architectures support such modules and facilitate smooth application updates. 

4. Integration Layer 

Through AS400 modernization, businesses can resolve the integration challenges in enterprise applications. By migrating AS400 enterprise applications to cloud or microservices architecture, IBM i modernization experts configure and connect API gateways and middleware solutions with the applications. These gateways enable AS400 applications to interact with various third-party systems and tools and facilitate secure data capture and exchange. This helps businesses automate diverse workflows and improve AS400 application adoption among internal teams. 

Conclusion 

Businesses that depend on AS400 integrated servers for application hosting should opt for modernization to ensure high operational excellence. However, AS400 modernization techniques like re-platforming, reengineering, and refactoring require in-depth evaluation, planning, and technical expertise. In such a scenario, businesses should consider hiring dedicated experts from an IBM i modernization company. The dedicated IBM i experts audit the AS400 application infrastructure to evaluate and determine the optimal modernization approach.  

Even after modernization, experts monitor the AS400 application infrastructure. This monitoring enables them to identify and troubleshoot performance and security problems with a minimal turnaround time and eliminate adverse consequences.