The first step in any mainframe migration project is developing a clear picture of your starting point and target platform. A complete mainframe modernization assessment or mainframe discovery is critical to identify risks, build a roadmap, and ensure project success.

Unfortunately, that can be a lot harder than it may sound. Most mainframe systems have evolved slowly over an extended period of time, – and in many cases, the people who know those systems best are no longer around. As a generation of mainframe engineers reach retirement age, there is a great deal of institutional knowledge that will be lost when they walkout the door.

Why do you Need a Mainframe Assessment?

No two mainframe environments are ever exactly the same. Fortunately, a lot of mainframe customers have a solid understanding of what’s running in their environment, – but very often, there are gaps, and before you can move forward with any mainframe modernization strategy, you need to understand exactly what you’re working with.

A typical legacy system has seen many years of use. It may have been implemented two, three, or even four decades ago. Despite the fact that stability is a core characteristic of mainframe systems, most have been modified at various points along the way to address evolving business requirements.

In fact, it is that very stability that can sometimes be problematic. Code that was originally written and compiled several decades ago may still be running perfectly well. That’s great, but an all-too-common side-effect is that the original source code has been lost somewhere along the way. It’s frequently the case that no one knows exactly what that code is doing, or how to handle it in the context of a mainframe modernization project.

We also see a number of situations in which code has been modified, bypassing entire procedures and rendering existing code obsolete. It’s still there, but nothing is making calls to those procedures. It’s orphaned code, no longer serving any purpose. Without a systematic analysis, though, you might not know what’s currently in use versus what’s not.

The end goal of the assessment process is to fill in these kinds of gaps, – to provide our customer with a complete picture of what is happening on their mainframe system. Only then can they begin to evaluate their options, – whether that’s a lift-and-shift approach, code conversion and migration to a relational database, replacement with commercial off-the-shelf software (COTS), or some combination of the above.

As a global leader in mainframe modernization, Astadia has successfully executed on numerous projects over the years, including some of the largest and most complex mainframe systems on the planet.

Our goal has never been to steer our clients toward any single approach. We’ve done it all, – and our overriding objective is always to help our customers select the approach that best serves their needs. We help our clients identify their options, understand the advantages and disadvantages of various approaches, and map out a path that will get them there.

That often hinges on priorities. Some clients approach Astadia with a fixed timeline in mind; very often that may be driven by contractual dates and personnel changes. Others place their highest priority on risk mitigation, taking a slower, stepwise approach to the overall process. The mainframe modernization assessment process doesn’t necessarily place a higher or lower value on any of these factors, – our goal at this stage is simply to report the facts.

The Art and Science of Mainframe Assessment

We often describe the mainframe assessment process as a combination of art and science.

The “science” portion of the process involves a systematic analysis of the mainframe application inventory. Astadia ingests the entire application inventory, including JCL, BMS maps, and numerous other components. Those go into a dedicated repository that sits outside of the mainframe environment. It’s important to note that at this point, we’re not looking at any data, and we’re not running anything on the mainframe itself. This stage starts with the client providing Astadia with all of their source code for a detailed analysis.

Our tools look at every procedure call. We look for any gaps in the source code, for example. If source code is missing, we can then have a conversation with the client about how to approach that problem. Solutions might include re-writing that code from scratch, or potentially reverse-engineering it using existing tools. Each of those approaches has its advantages and disadvantages, – but our primary focus in the assessment process is simply to report the facts.

At this stage, we’re also looking for code that’s no longer used, and for variables that are defined but never used. Although we don’t look at actual data, we do perform an analysis of data structures. That may point toward opportunities to normalize existing data, migrating to a modern relational database.

A key deliverable that comes out of this process is a graphical representation of the client’s existing mainframe system. That can often highlight areas that may be candidates for replacement, versus higher-risk components that may be better left untouched.

The next stage is where the “art” of the mainframe modernization assessment process comes into play. Our subject matter experts engage with the client's subject matter experts to ask about specific areas like security and infrastructure and coding practices. This is where we uncover some many of the unique aspects of our customer’s environment. We may learn, for example, that they wrote their own custom database handler forty years ago. By talking to the customer’s in-house experts, we can understand why they did that, and how it might impact plans to move forward with a mainframe modernization project.

The end result of the mainframe assessment process is a detailed understanding of the customer’s existing environment, – not based on an anecdotal understanding, but rather on a thorough, systematic analysis of the client’s existing application code.

FastTrack Assessment by Astadia  

An Astadia FastTrack assessment is a unique offering to accelerate your mainframe to cloud journey. Astadia builds on a 25-year history of migrating mainframe workloads to distributed and cloud platforms to provide a comprehensive understanding of your current environment and identifies the best in-industry solution for your unique mainframe to cloud journey.  

Why FastTrack by Astadia?  
Tool Agnostic  

As an outcome from a FastTrack assessment, a customer will receive multiple proposals, and easily be able to compare and contrast options such as replatforming mainframe workloads to COBOL or refactoring to Java and C#. This is the only offering in the mainframe migration industry that leverages multiple assessment tool sets, based upon the requirements of the customer. No two mainframes are alike, and each migration project will come with its own unique set of complexities and risks that may be better suited to one tool over the other.  

Pattern Agnostic  

Astadia prides itself on being an “honest broker” in the mainframe migration industry. As a pattern and solution agnostic company, Astadia takes a consultant-first approach with our customers. We collaborate with our customers to develop a detailed and thorough understanding of their current environment, and their future goals, and then identify the pattern that makes the most sense based on our customers requirements.   


A key to a successful mainframe migration is working with a partner who has done it before. Mainframe applications are often 20+ years old, undocumented, and many of the folks who wrote the code and are familiar with the business logic have moved on from the company, or plan to do so in the coming years. Astadia allows customers to benefit from the recommendations and guidance of experienced consultants to find the lowest risk migration path with the highest probability of success for their unique environment and their specific goals. Astadia has been in the mainframe migration business for over 25 years, with our average consultant having 26 years of mainframe experience. From over 300 completed projects, we provide customers with actionable insights based on past experiences.

As Astadia engages with new clients for the first time, the mainframe assessment process provides us with a clear and comprehensive understanding of what we’re working with. It’s that vital preparation phase that sets the stage for a successful modernization project.

Want to learn more about how you can benefit from the FastTrack Mainframe Assessment? Get in touch.

Related white papers:

The Astadia FastTrack Mainframe Modernization Methodology

Learn how to eliminate risk from software transformation projects by using an innovative approach and a powerful suite of automation tools.

Download white paper
The Astadia FastTrack Mainframe Modernization Methodology

Let's Talk

Get in touch with our experts and find out how Astadia's range of tools and experience can support your team.

contact us now