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Learn how the worlds largest organizations are solving their largest IBM mainframe challenges in 2020.


Largest IBM Mainframe Challenges Faced in 2020

Posted by OpenLegacy on July 21, 2020
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Mainframes have come a long way since IBM first introduced these processing powerhouses back in 1952. The latest IBM Z series mainframes offer advanced capabilities, flexibility, security, resilience, and support multiple operating systems.

Although IBM has invested significant efforts into improving the functionality and capabilities of its mainframes, organizations that rely on mainframe-dependant applications are facing the same problems that plague other monolithic legacy systems.

In order to keep pace with the speed of innovation in the IT industry, enterprises need to find solutions that would enable them to leverage their existing mainframe assets while simultaneously allowing them to integrate new systems and technologies.

Redefining mainframe modernization

OpenLegacyIn today’s digital business world, the success of an organization is often measured by its ability to adapt to change and the speed at which it can embrace innovations. While change is risky and mainframe modernization comes with its fair share of challenges, doing nothing is a surefire way to spell the end of your business.

Customer and business needs are rapidly evolving, as modern technology introduces new capabilities. Failing to keep pace with the innovations will make your current business model unsustainable in the long run, as the mainframe maintenance cost increases, while your time-to-market slows down.

There’s also the threat of increased business competition — nimble startups aren’t constrained by legacy systems and can leverage new technologies to launch digital innovations almost overnight.

Although mainframe modernization is a necessity, it doesn’t have to be an extreme decision to move away from the mainframe completely. You might plan to modernize and migrate away from the mainframe eventually, but the fact is they are here today, and companies rely on mainframe-dependant applications for core business functions.

This means mainframes need to be leveraged for the digital world today. OpenLegacy provides an excellent alternative by enabling your organization to utilize microservices and APIs to create digital services from the mainframe. This way, you can leverage the valuable assets in your mainframe to deliver digital services with speed and efficiency and can gradually migrate off the mainframe rather than having to make a radical decision.

The challenges of mainframe modernization

We understand that migrating off the mainframe is a lengthy process and one that requires thorough strategic planning. That’s why we believe leveraging microservices and APIs is the best option. OpenLegacy enables organizations to deliver digital services without making any changes to the mainframe, allowing you to make the migration gradually, while largely removing the associated risks and costs.

Here are the key issues and challenges related to the now six-decade-old mainframe technology that OpenLegacy can help you overcome.

Mainframe-dependant applications are behemoths that are hard to wrap your head around

Updating or enhancing legacy applications can prove to be difficult due to:

  1. The lack of understanding of the business flow of the legacy application — lack of documentation
  2. Difficulty in finding legacy application technical sources (aka Cobol Programmers)
  3. The cost of actually increasing an enterprise technical debt

The interdependence of all the different technologies implemented in a mainframe application makes it extremely difficult to make any changes or scale the application’s capabilities. Adding new features and functions can be scary, since even the smallest of changes can break the entire application, resulting in days, if not weeks of downtime.

Given that mainframe applications enable organizations to perform critical business functions, it’s necessary to have a comprehensive, fully tested disaster recovery and a backup plan in place.

Another issue with legacy applications deployed on mainframes is that their complexity makes them extremely difficult, if not outright impossible, for a single person to understand. This is especially true if the previous developers have left the company or if individual changes to the application weren’t properly documented.

Without fully understanding how all of the aspects of a mainframe-dependent application are interconnected, nobody can predict what effect further changes will have on the application as a whole.

Still, in today’s business environment, organizations don’t have the luxury of maintaining the “if it ain't broke — don’t fix it” attitude. While the application may still serve its original purpose, the changes in code implemented over the years may cause it to no longer be efficient. The increased complexity often results in poor response times and inefficient use of processing power, making the application on the mainframe increasingly expensive to maintain and run.

At times, it seems like you’re stuck between a rock and a hard place. On the one hand, you’re stuck with a legacy system that doesn’t integrate with new technologies and doesn’t support innovation. On the other hand, migrating to newer technologies can be an expensive, time-consuming, risky endeavor.

OpenLegacy abstracts this choice by allowing you to create modern microservices and APIs that pull data directly from the mainframe. Read our detailed eBook called “Accelerating the Digital Journey from Legacy Systems to Modern Microservices to see how you can leverage the mainframe for digital services today.

Mainframe maintenance is extremely expensive

Despite the fact that IBM rolled out the IBM System/360 in 1962, many enterprises still rely on mainframes for their mission-critical applications. Although a good number of them fear the uncertainty of change and the risks associated with modernization, it’s become difficult to ignore the increasing costs associated with mainframe maintenance.

Let’s take the finance industry as an example. According to IBM’s statement from 2017, 92 out of the world’s 100 leading banks relied on IBM mainframes at the time, and most of them still do. The main reason is the mainframes’ ability to process incredible volumes of transactions extremely efficiently versus the alternatives.

The problem, however, is that these legacy systems do not integrate with modern systems and are growing increasingly complex with each update, which makes them more difficult to maintain. Banks spend over $200 billion a year on IT, and Citigroup estimates that nearly 80% of that money goes towards maintaining mainframe-dependent legacy systems.

Transitioning to the cloud and embracing microservice-based APIs could cut the maintenance cost by as much as 75 percent! When you look at these numbers, mainframe modernization/transformation becomes a no-brainer, regardless of what industry your organization is in.

This doesn’t necessarily mean you have to “get off the mainframe.” OpenLegacy provides you with a way to modernize your legacy applications and extract value from your existing systems — today — while at the same time laying a path for the future.

See how OpenLegacy can help you leverage microservices to fast-track the modernization of your legacy systems.

Younger developers are future-oriented

Another growing concern of organizations that rely on mainframe systems is the lack of specialized experts with the knowledge and skills required to handle the complexity of mainframe-dependent applications.

The old generation of developers who specialized in COBOL and assembly language code is retiring and making way for younger developers.

New developers in their twenties who are looking to make a career in IT today aren’t too keen on working on old, outdated technologies. They were brought up on point-and-click and modern productivity features and are mainly focusing on cloud platforms and modern development tools.

This shortage of mainframe-savvy staff can put your mainframe data and applications at risk regarding both performance and security. There is a resurgence in Cobol training classes, due to huge demand, but that likely means you’d have to invest additional time and resources to provide the required training to new hires.

OpenLegacy’s approach eliminates the need for mainframe experts, as Java developers can interact with mainframes directly using our integration platform, all without making any changes to the underlying system.

Mainframe development requires separate pipelines and processes

Modern software development pipelines streamline everything from build processes, testing, and source-code management to integration and deployment. By leveraging modern tools, developers can promote locally-tested changes and have them flow through an automated testing pipeline.

The mainframe environment within an enterprise did develop a structured development/deployment process. This process was built to accommodate the inherent risk of making any changes, so it involved numerous testing and QA stages. It was also built around the premise that you only made updates to your mainframe production environment on a scheduled basis — sometimes only three or four times a year. If you missed a cycle, you needed to wait. So what blossomed with the mainframe environment is a Culture of Bureaucracy versus a Culture of Change that we find ourselves in today.

Limited automation and increasing expense of testing

In a modern development pipeline, testing is an automated, continuous, and highly scalable process. With modern applications architecture that relies on the cloud and microservices, developers can launch containers with a single click at any testing stage. This is one of the main reasons why modern application development is infinitely faster than developing an application on an IBM mainframe.

Given the physical hardware dependency of mainframe applications and the complex interdependence of various technologies within a mainframe environment, testing individual components in a mainframe application is simply impossible. With a microservice architecture, developers can create, test, and deploy individual microservices completely independently of the application as a whole. Furthermore, developers can rely on modern tools to fully automate the testing, allowing them to reduce deployment time and costs significantly.

There’s also the issue of large-scale performance and regression testing. In mainframe-dependent applications, full performance and regression tests require extensive resources and planning. With modern applications, organizations can schedule fully automated performance and regression tests in a much more cost-effective manner.

With legacy mainframe applications, you would have to test the entire application every time a change is introduced into the system. In addition, testing legacy applications built on mainframes requires organizations to include mainframe system administrators and utilize expensive mainframe resources.

A perfect solution to the IBM mainframe modernization conundrum

One of the most efficient ways to embrace innovation and integrate new technology with legacy mainframe applications is leveraging microservices and microservice-based APIs. That said, utilizing microservice-based APIs to access the wealth of data and business logic stored inside IBM mainframes (z/OS) has been a painstaking and extremely slow process until recently.

The main challenge is prioritizing backlog projects and aligning them with your business needs. On top of that, tools like IBM’s z/OS Connect require dedicated liberty servers and IBM Z series certified engineers.

This way, it might take you more than a month to get everything installed, and you’d still have to build a facade for data translation and rely on middleware to transfer the data. Even then, the resulting APIs won’t be cloud-native microservices or nodeJS functions since their dependency on the mainframe would still require the developers to adapt them to the existing mainframe environment.

The added layers of complexity, platform upgrades, and manual development are in direct conflict with most organizations’ primary business objective — reducing the time-to-market. This is why it is necessary to adopt a different approach to legacy API creation, one that would allow you to better leverage the IBM mainframe assets and speed up API deployment.

The OpenLegacy platform uses built-in connectors to connect to the mainframe automatically and allows organizations to generate microservice-based APIs for deployment in the cloud or on-premise. With OpenLegacy, you can create and deploy APIs ten times faster than with IBM’s z/Os Connect, and with fewer developers!

OpenLegacy allows you to modernize your IBM mainframe without the typical complexity, middleware, cost, and risk — at a fraction of the cost. With our platform, you can deliver outstanding digital services in weeks, rather than months.

How OpenLegacy compares to IBM’s z/OS Connect

For most enterprises that rely on IBM mainframes, it’s only natural to turn to IBM for a modernization solution. It makes perfect sense that the company would offer such a solution. IBM understands well that new technology, like the cloud, microservices, and APIs, has reshaped the way in which modern applications are developed.

Without a way to integrate these new technologies with their existing IBM mainframes, a good number of enterprises would leave the legacy mainframes in favor of modern solutions, resulting in IBM losing a good portion of its clients.

This is one of the main reasons why the company developed IBM z/OS Connect — a framework designed to enable z/OS-based applications and data to leverage microservices and APIs for mobile and cloud applications.

Although IBM z/OS Connect does offer a way to incorporate legacy assets into modern digital architectures, you need to ask yourself if it’s the most efficient solution to your organization’s mainframe modernization problem.

In order to help you understand better the limitations and hidden costs of IBM z/OS Connect, here’s a comprehensive table that explains how IBM’s modernization solution stacks against the OpenLegacy platform.

IBM z/OS Connect vs. OpenLegacy


z/Os Connect



Necessary requirements for mainframe integration to work

The requirements for integration through z/OS Connect include:

  1. A dedicated logical partition (LPAR)
  2. Going through the USS side of the mainframe
  3. A liberty server
  4. Latest versions of all software components

You only need 3 RDO resources for CISC. There are no setup requirements for IMS


Interpreting the COBOL Copybook

You must invest considerable efforts to manually translate legacy parameters-areas and create APIs the users will understand



Making the Cobol Copybook an easily understandable, maintainable, and consumable JSON

Standardization in z/OS Connect has proven to be a challenge for developers since IBM’s solution can be difficult to understand and maintain

Easy to understand and consume JSON generated through automated tooling


Connectivity from the service to the mainframe

Effective tooling – vendor lock-in and highly proprietary

Effective tooling based on open standards


Wrap the service as a Microservice, with the flexibility to deploy across different environments

Not available

Automatically generated with clean APIs, private functions that pull data directly from your legacy system, and Docker for easy loading onto any system


Configuration and injection ability to adopt in-house best practices, security standards, etc.

Not available

Full flexibility — The generated code is standard Java and can be fully modified, either directly or through templates


How the integration aligns with DevOps

Not available

Full Support — Microservices with clean APIs perfectly align with DevOps. Standard Java with JUnit testing and full automation is also included


Given the high setup requirements, lack of standardization, and vendor lock-in, maintenance is painful

Maintenance is made easy since the platform is based on open standards. It’s just as easy as maintaining any Java application

To sum it up, z/OS Connect is merely a translator from COBOL copybooks to JSON. You’d still need to invest an enormous amount of time and effort in setup and maintenance.

While you would technically be able to leverage modern development technologies, the long development time would still lag behind modern startups when it comes to delivering services to the market. The bottom line is that z/OS connect only adds more layers of complexity and reduces agility, effectively preventing you from meeting your business goals.

The OpenLegacy platform is a modern, comprehensive solution for mainframe applications. It allows you to leapfrog decades of technical debt without paying the price of a migration. Here’s a case study of a Panama branch of a leading bank that aligned mainframe with DevOps to speed time-to-market by 50% and reduce costs.

Business case — How OpenLegacy succeeded where z/Os Connect failed

Migrating from monolithic legacy systems to modern microservices can be quite a challenge. One of our clients was a leading Israeli bank that struggled with complex and heavily customized ESB layers that hindered access to their IBM stack. Despite extensive planning and testing, they couldn’t solve the issue with IBM’s z/OS Connect.

With the OpenLegacy platform, the bank managed to bypass the complex layers and drastically increase the speed of deployment of microservice-based APIs. By partnering with OpenLegacy, they managed to create five microservices in just two weeks, with a single developer!

Download the case study and see how we helped the leading Israeli bank efficiently migrate their mainframe to microservices, and get a better idea of what OpenLegacy platform can do for your organization.


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