Legacy mainframe applications have endured for decades and often these applications are well suited to the business's needs and provide functionality and capability that could not be easily replicated through a rewrite or replacement modernization approach.

Refactoring mainframe applications to Azure is a popular pattern pursued by many organizations and consists in automated conversion of applications in languages like COBOL to Java or C# and to leading relational databases on Azure. This approach enables applications to be in modern programming languages, with modern databases, and in platforms that the next generation of developers can easily maintain and innovate upon.

Java and C# are some of the most widely used programming languages today and often a language of choice for many IT programs in schools across the globe. Moving from COBOL to either one of these languages enables the usage of state-of-the-art IDEs, thousands of third-party libraries, and modern application architectures.

Microsoft Azure is an excellent target environment for transitioning from an IBM mainframe workload to a cloud implementation. With the security features of Azure and the ability to scale based on demand for the services, Azure offers a complete operational environment in support of mainframe workloads that have been migrated to the cloud.

In addition, Azure supports innovation of the application portfolio, previously held captive by the inflexible nature of a mainframe computing model, improving the productivity of application developers and support personnel.

Migrating to Azure allows clients to leverage numerous cloud services and scale their applications on demand.  

The FastTrack Factory: 100% Automation

With pressing drivers compelling mainframe customers to look for alternatives, Astadia has successfully provided a proven path forward. By developing The FastTrack Factory - the only fully automated migration software platform on the market -, Astadia partners with clients to migrate their mainframe applications to cloud or distributed environments.

The platform provides 100% automated migration and testing, which are critical in accelerating and ensuring a successful mainframe migration, while maintaining applications’ functional equivalence.

See how organizations can reach faster time to market with reduced project risk>

A Complete Mainframe-to-Cloud Migration Solution

Astadia provides a full suite of automated migration and testing technology for transformations from one technology to another. The FastTrack Factory software platform has one crucial consideration: each organization is different, and each migration is different. Every client has its development and design standards, patterns, and frameworks.

The Factory is therefore highly configurable. It consists of several language parsers, analyzers, rule-based converters, and generators that work together to perform complex transformations on existing source code. These converters and generators can be easily configured to produce optimal code.

For example, if your organization has implemented specific standards for coding, our CodeTurn tool can be configured to incorporate those standards into its transformed application code.

Here is a quick overview of the migration platform’s main software components:  

  • CodeTurn – Provides automatic source code conversion. CodeTurn supports many different source languages, such as COBOL, Natural, and CA ADS. The most typical target languages are COBOL, Java, or .NET.
  • DataTurn - Provides specialized features for various source databases, such as Adabas, IDMS, DB2, IMS, VSAM,ISAM, and target databases such as SQL Server, Oracle, or DB2. The target database can be accessed natively without restrictions.
  • TestMatch - Automated Record and Replay testing for online and transaction-based applications such as3270, MQ, and EntireX. TestMatch provides functional tests, performance tests, and stress tests.
  • DataMatch - Automated testing for data-centric and batch programs. The tool compares databases after running batch job on mainframe, with after running converted batch job on the target platform.
  • CobolBridge – A VSCode based IDE that allows for the editing and debugging of COBOL while running Java or C# in the backend. COBOLBridge uses CodeTurn and COBOL tools as part of the 'build' process, producing maintainable Java or .NET. Customers can take time tore-train COBOL developers and then decide to start maintaining Java/C#.

Learn more about the Astadia FastTrack Factory >

Licensing the Factory: An Industry First

In addition to providing complete end-to-end services for mainframe migrations, clients or partners can choose to license the platform to deliver projects themselves. This is a critical factor when evaluating migration partners – do you have the ability to license their software? The answer to this question must be yes, as it ensures you're dealing with a complete product that requires little manual intervention.

Often, providers in the refactoring and mainframe to cloud market will position tools that automate 70-80% of the process and require the remaining 20-30% of the development work to be done by hand. This creates both significant challenges and costs, whereas a fully automated solution will be a complete product.

FastTrack white paper

Proven Methodology

In addition to the Migration Factory, Astadia’s mainframe migration to Azure solution relies on our FastTrack methodology, that has been developed over 20 years and refined over hundreds of mainframe migration projects.

Astadia's FastTrack process is an innovation that eliminates risk from software transformation projects and allows applications to undergo complex cross-platform migrations at the same time as normal perfective and adaptive maintenance progresses without business interruption.

With comprehensive and fully automated technology and a proven methodology focused on accelerating the mainframe migration and driving down risk, Astadia enables clients to migrate their mainframe applications to Azure at a speed and scale unlike any provider or solution in the industry.

IBM Mainframe-to-Azure Reference Architecture

The following Reference Architecture diagrams address a typical mainframe to Azure use case. However, each implementation is sure to have its own customizations and variations, which is why a thorough application portfolio inventory, assessment, and rationalization is critical to a successful outcome.

The typical mainframe migration to Azure process includes Azure components, batch requirements, programming language conversions and replacements, integration with external systems, and planning for future needs. In an actual project, you would also consider any unique features that would necessitate custom-made solutions. We would recommend proof-of-concept conversions on application subsets to test the model selected, discover any weaknesses, and prove the viability of the design.

The newly transformed applications will run as a native first-citizen application on Azure. The Astadia technology does not rely on emulators or sandboxed applications. The Migration Factory tooling keeps the transformed code concise, readable, and maintainable, without code bloat, by centralizing code sections within libraries and software services. These become an integral part of the generated code, delivered in source code format. There is no vendor lock in, and newly written code does not need to rely upon the source libraries.  

Modernizing mainframe applications is the most critical phase of the total project effort, even more than a typical IT project. An excellent place to begin is with a thorough assessment of the existing overall mainframe application portfolio. All aspects of the current portfolio will be inventoried and examined in detail through the assessment process, resulting in a catalog of each application, database, technology platform, and business user profile currently in use.

Once completed, the results of this application rationalization will then guide the sequence of application migration and the different modernization strategies and techniques that may be called upon throughout the entire project. To learn more about getting started with an assessment, reach out to us here.

Your Cloud Environment

Azure Virtual Network (VNet) lets you provision a logically isolated section of Azure where you launch and manage interconnected resources in a virtual network that you define. It’s your private area within Azure. You can think of this as the fence around all the systems you have in Azure. You have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways. You can also integrate your on-premises network using a VPN tunnel or Azure Express Route Service.

Computing Resources

Azure Virtual Machines (VM) is one of several types of on-demand, scalable computing resources that Azure offers. Typically, you would choose a VM when you need more control over the computing environment than the other pre-configured choices offered. For mainframe workloads, this serves as the foundation upon which your applications sit. It’s the container that holds the operating systems, mainframe emulators, application executables, and other supporting soft ware that make up your application.

Depending on your specific circumstances, you may separate some pieces into their own Azure VM instances or you may run everything in one VM. For instance, maybe you’ll have an Azure VM dedicated to batch COBOL and another dedicated to Online. You may even segregate VMs by application, application types or maybe by the databases they access.

Each organization has unique needs and specific requirements. The number of VMs that your applications use can scale up and out to meet your needs. You’ll also configure VMs dedicated to specific tasks, such as the development and maintenance of your migrated applications and various testing environments.


Azure Storage services can be thought of as hard drives for storing your data. It provides the storage foundation for Azure Virtual Machines, is massively scalable and can store and process hundreds of terabytes of data to meet the demands of your migrated applications.

Azure Storage uses an auto-partitioning system that automatically load-balances your data based on traffic. This means that as the demands on your application grow, Azure Storage automatically allocates the appropriate resources to meet them Azure Storage is accessible from anywhere in the world, from any type of application, whether it’s running in the cloud, on the desktop, on an on-premises server or on a mobile or tablet device. Services include Disk storage, Blob storage, Queue storage and File storage – each with its own specialized characteristics.


Legacy relational data will reside in database VM instances. This includes any hierarchical and flat file data that’s been converted to relational. For example, all your IMS DB data would be converted to relational data and stored in a VM running SQL Server or other database products like DB2 LUW, Oracle or MySQL. DB2 data would also be migrated to one of these VMs.

Azure SQL is optimized for database performance. It’s cost-efficient, has resizable capacity, and is designed to reduce time-consuming database admin tasks. However, it’s best suited for new databases rather than legacy data. You’ll most likely utilize dedicated VMs running SQL Server or another RDMS product like Oracle.

Azure also offers other database services like SQL Data Warehouse for data warehousing, SQL Server Stretch Database to stretch on premises databases to the cloud, and Azure Cosmos DB for globally distributed, multi-modal databases. An analysis of your existing legacy databases and applications will reveal all the changes required to migrate your data to Azure as well as which database services make the most sense for your migrated applications.

Jefferson County case study

Why Migrating Your Mainframe?

The IBM z/Series mainframe continues to provide a stable, dependable, and high-performance platform for large enterprises across the globe. It has proved to be an enduring system, continually outliving the expectations of analysts and experts. With over 250Blines of COBOL worldwide, the mainframe lives on, running large mission-critical applications at a massive scale. With all the strengths it has to offer, the question becomes why invest in a mainframe migration?

There are many documented failures, and a mainframe modernization project is often perceived as high-cost, high-risk, without a clear return on investment. At Astadia, we are answering these questions for the largest mainframe customers across the globe. No longer are migrations the pursuit of customers with 100 MIPS, but those with 10,000 MIPS,50,000 MIPS, and more are setting the direction to exit their mainframe. Why is this happening now, in 2021?

The Urgent Need for Innovation

There are several reasons why the demand for mainframe modernization is rapidly accelerating among organizations worldwide, but primarily, the need for innovation has never been more pressing. All industries face disruption, and without the flexibility to adapt and adopt new technologies quickly, businesses are at high risk of failure.

CIOs routinely report their mainframe and COBOL applications are not suited to doing business in the new normal. The pandemic accelerated digital transformation across all areas, and 5- and 10-yearroadmaps have been thrown out the window. Technology's strategic importance in business is evident, and innovating is no longer a matter of optimizing budgets and addressing technical debt but a matter of survival.

The Skills Shortage Risk

The growing talent gap is a well-documented issue. Despite the best efforts of a few universities and programs, there is nowhere near an adequate amount of education to train a new generation of COBOL programmers. COBOL programmers are, on average, less than five years away from retirement, and for many, that number has been accelerated due to the pandemic and changed work-life priorities.  

Increasing License and Maintenance Costs

Lastly, there is cost. The high prices are often acutely experienced by customers running products such as CA IDMS or CA Datacom (who CA lovingly referred to as "cash cows in the basement"). Azure offers clients the opportunity to pursue significant operating cost reductions and reinvest that money into further modernization programs.

Astadia has documented references of customers saving upwards of 80%, with some of our large customers reducing their annual operating costs over $20M and achieving payback periods of less than 12 months.


A mainframe migration to Azure is one of the most impactful initiatives an organization can pursue today. With significant return on investment, unlocking your legacy mainframe applications opens up a multitude of possibilities for innovation and transformation.

A two-phased approach to modernization, is a simple, but proven framework that has worked for hundreds of clients. The first phase is to retire the mainframe and land safely in your new Azure environment, followed by the second phase of adopting strategic modernization initiatives to meet your future goals.

A complete and fully automated approach enables mainframe customers to pursue modernization without compromise. Moving from COBOL to Java or C# requires a fully automated migration and testing platform a partner with extensive experience and case studies, and a proven methodology.

There are many considerations to make when embarking on a mainframe to cloud journey. At Astadia, we have encountered over 40 different technologies on our customers mainframes, with each environment coming with its own set of challenges. If you'd like to understand how this could be possible for your organization's unique complexities, we'd love to hear from you. Fill out this form to get started.

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