Software Modernization of Legacy Systems

PASS Migration Factory replaces your legacy software

Fully-Automated Legacy System Migration

Software modernization on all levels

The end is looming for costly old platforms and for very good reasons: The number of experts with insight into legacy systems is constantly declining. IT budgets are strained by hefty license and maintenance costs. But most of all, the company is downright cut off from technical advancement.

Software modernization and the migration to new platforms are high on the list of priorities for IT divisions. But companies are finding the shift from old systems to new platforms anything but easy, regardless of the related perspectives on flexibility and simplification. By migrating the code automatically, we make legacy modernization projects far less menacing. Thanks to our Cross-Platform Technology cpTech, an automatic legacy system migration to modern platforms such as Linux, Java, Web etc. is generally 100% possible.

Our method: How our fully automated legacy modernization works

Migration into intermediate language  Migration into intermediate language: The code structure of the source code is parsed, analyzed and converted into an intermediate language developed by PASS (XML).

Multi-stage migration  Multi-stage migration: Multi-stage repeatable transformation of the migration model to prepare for migrating into the target environment.

Migration into target system  Migration into target system: The target code migration takes place. The final XML intermediate language is migrated in the desired target format and adapted to the style guides of the target environment.

Migration Layers

Mask Migration

The interface migration is fully automated and adapted to your needs – for this we use the latest web technologies (JSF 2, Angular with TypeScript, HTML5). We will advise you which solution fits best for your application scenario.

In practice, the requirements are quite different: They vary from application scenarios in which the look & feel should correspond to that of the legacy application, up to scenarios, in which a migration to a single interface is requested, that supports the opportunities of modern GUI elements.

Another highlight of our modernization technology is the PASS GUI editor, which enables cross-language customizing and extension of the migrated interfaces without adapting the source code.

Language Migration

The business logic is migrated automatically over several production stages, based on mapping rules. First of all, the source code of the source environment is transformed into the PASS Intermediate Language Specification (PILS). From this, the transformation into the target language and architecture is carried out automatically over several consecutive steps. At this stage, individual adjustments in customizing can be made, e.g. regarding the look & feel of the source code as well as the implementation into your application architecture by integrating the generated result directly into your runtime environment.

The procedure we propose contains a clarification of the expected result in advance. We are willing to show you an exemplary language migration in advance.

Script Migration

The requirements for the target environment of a script migration are different - accordingly we offer several scenarios:

  1. Scripts of the source platform (e.g. JCL) are migrated into the shell language of the target environment (on Linux e.g. Bash or Korn Shell).
  2. Scripts of the source platform are migrated into (BPMN) processes of a process engine or job scheduling system. The flow paths of the scripts become very transparent when displayed in BPMN, for example.
  3. Scripts are migrated into sequential programs, e.g. in Java.

During the “Quick Check” phase we will discuss the most suitable solution option with you

Architecture Migration

In most cases, modernization projects are accompanied by a change in architecture. We can support our customers with numerous architecture migration templates. This includes e.g. migration of:

  • a rich client or terminal emulation to a browser client,
  • business logic into a 3-tier architecture and
  • transaction systems to an application server that supports transaction management.

Data Migration

Mostly any software contains a data layer. It is often necessary to upgrade it to a different technology within a modernization project, either due to high license costs, insufficient staff resources, a missing reporting function or the use of a replicated mirror database. The reasons for that can be very different.

We offer you an automated conversion of your data with the help of cpTech. It achieves transparent, reliable and cost-efficient results. We also support migrations from file formats to relational formats (e.g. VSAM or hierarchical databases to relational databases, character set conversions, etc.).

Platform Migration

In addition to the migration of individual technologies, there may also be the goal to operate the application on another platform, for example in order to reduce operating costs.

Talk to us about your project and we will have our experts develop a possible scenario based on your requirements. Among the services we support is the migration from a host to a Linux platform.

4 Ways of IT Modernization [Infographic]

Legacy systems have no future in the medium term, that much is for sure. But what suits best when? Migration, new development, standard software or outsourcing: four ways of IT modernization – graphically visualized for you.


View Infographic

Highlights of the PASS Migration Factory

Minimal frozen zone

Minimal frozen zone

Further development can continue even while the legacy software migration project is underway.

Integrated customization

Integrated customization

Once migrated, the target code can easily be configured and aligned in accordance with the customer’s style guide.

Serviceable source code

Serviceable source code

The migrated source code is fully serviceable, thus nothing stands in the way of further development.

Benefits of Software Modernization



  • Quality gains thanks to higher performance (process optimization) and state-of-the-art technologies (GUI etc.)
  • Efficiency boost (particularly in product development) due to a shorter time-to-market


  • Cost-cutting
  • Reduced maintenance required
  • Focus on optimization
  • Flexibility: business requirements implemented more swiftly
  • Quality boost due to higher process security
  • Future-oriented technology


  • Cost reduction (maintenance, investment and operation)
  • Increased efficiency thanks to a shorter time-to-market
  • Flexibility for your IT strategy
  • Future-oriented technology

What Makes PASS the Right Partner for Your Software Modernization

Long-standing expertise

More than 15 years of practical experience in implementing legacy system modernization projects.

Accelerated project terms

Thanks to almost 100% automation, the legacy system migration process literally proceeds at the touch of a button.

High procedural security

A proof of concept provides an early indication of the success to be expected from the legacy modernization project.

Automated regression tests

Support for automatic comparison/regression tests

An exemplary legacy system migration scenario

Project phases of the software modernization

We are technology specialists in the field of automated legacy modernization. In the course of numerous software modernization projects we developed our Cross-Platform Technology (cpTech), making the switch to new and cost-efficient platforms possible. We calibrate our robots to meet project-specific requirements, generally allowing us to reach automation ratios up to 100%.

The projects often take place in two periods, with a preceding quick check, which verifies the basic feasibility. The time period, even for extensive modernization projects, has always been within a year.

In advance: Quick check (optional)

Analysis of your initial situation

In a first step, the existing sources and documentation of the legacy system are reviewed. Source types, (third-party) components and interfaces are identified and an appropriate modernization concept is defined. The execution of a risk analysis and the definition of the project scope are also part of the quick check.

The objective target is to verify the basic feasibility of the migration project.

Phase 1: The evolutionary Prototype

Safeguarding your investment


  • Verify the feasibility of the desired migration by evolutionary prototypes
  • Gain a high degree of reliability after a short time by choosing a representative use case
  • Set out the entire expense and timeline of the project in detail

As part of the proof of concept (feasibility study), a prototype legacy system migration is performed in order to gain a representative outline of the applications. Even at this early stage, we employ all steps of the Migration Factory process to the selected use case, including the initial calibration of the robots to the project requirements. Non-cognitive points can be excluded from the evolutionary prototype.


  • Evolutionary prototype
  • Final determination of the target architecture (hardware, operating system, programming language and more)
  • Mappings on architectural, design and command levels
  • Specification of interfaces and dependencies
  • Estimation of the expected degree of automation


Phase 2: The migration project

The four steps of automated legacy software migration

The migration robots specified in the evolutionary prototype are used for the entire modernization project.
With the target of a degree of automation close to 100%, the robots are continuously calibrated until the result is completely migrated in the target language.
The process steps calibration and test are used iteratively.
At the same time, the target architecture is set up in which the migrated code is embedded directly.
After completion of the automated legacy system migration, including confirmation of its correctness, the migrated system is committed to the customer's approval process and is set productive.


100% Automated Migration: Don’t Believe Us?

Some people are skeptical when it comes to a fully automated legacy software migration. Indeed special cases do exist, where transformation without manual intervention is not possible. But we have developed a solution for these cases based on intelligent adaptation of the production line.

Many successful software modernization projects prove that our Migration Factory is based on a sophisticated concept, in both technological and organizational terms:

    The Migration Factory is the outcome of more than 30 years of IT projects
    It boasts an unrivaled degree of automation
    The configuration is adapted to each individual project situation
    Automation guarantees security and risk minimization
    The Migration Factory is cost-effective, error-free and flexible

Let us prove the efficiency of our strategy to you!

By the way: we credit the costs of a preliminary proof of concept for your software modernization project to the project costs when you commission us.


Project Examples From Our Customers

Migration of a legacy systems from COBOL to Java

Degree of automation: 100%

Degree of automation: 100%

Migrate a central accounting system 100% automatically from COBOL to Java: PASS demonstrates that this is possible in a proof of concept for ista.

"To ensure the future viability of the core component, we want to replace the host-based components of the ABRE application with a modern Java and Web architecture. After evaluating the effort, risk and costs, PASS convinced us with their Migration Factory and we commissioned a proof of concept".

Andre Schmidt (Project manager, ista International)

  Read success story

Migration of a legacy system from PL/I to Java

Project duration: 5 months<br />Degree of automation: 100%

Project duration: 5 months
Degree of automation: 100%

By using the Migration Factory, PASS Consulting has succeeded in automatically generating 100% serviceable Java code subject to the KfW architectural model.

"We now know that a 100% automated migration is feasible using the PASS Migration Factory. The migration result is easy to maintain and the perfect basis for further development. Likewise, requirements in terms of code quality and performance have been met completely and thoroughly."

Volker Scheringer (Director, IT MIG – IT Strategy 2020 Migration at the KfW Bank Group)

  Read success story

Migration to CICS of all applications under the IMS/DC transaction monitor 

Project duration: 9 months<br />Degree of automation: 100%

Project duration: 9 months
Degree of automation: 100%

R+V Insurance advertised for external bids for the conversion of the subjects “Back” and “Life”. As a result of only one transaction monitor being in use, operational complexity should be reduced. In addition, licensing costs should be significantly reduced by the switch.

The following requirements were defined for the migration project:

  • All input screens under CICS should look exactly as they did under IMS/DC.
  • Performance should not be impeded in any way.
  • The business logic of the program should remain unchanged.
  • The conversion must absolutely be completed by a specified date.

PASS has won the bidding and meets both the requirements and the objectives of R+V.

Combined language and architecture migration of a complex settlement application
(> 1 million lines of code)

Project duration: 9 months<br />Degree of automation: 98%

Project duration: 9 months
Degree of automation: 98%

  • Architecture migration from BS2000 / terminal emulation to Linux/Web application
  • Language migration from COBOL85/JCL to Microfocus COBOL / Shell Script
  • Data migration of application data (ISAM data)
  • Numerous optimizations (SSL encryption, improved response behavior, increased robustness through generative additions of validations)

Through this migration, operating and maintenance costs of more than one million euros per year could be saved. Furthermore, the following objectives were achieved:

  • Better performance
  • Redesigned development technology: Eclipse, context-sensitive editor, graphical documentation, impact analysis
  • Test automation
  • Uniform production platform
  • Improved documentation

* Some of our customers prefer not to publish their projects for strategic reasons. If you have any specific questions about the project, please contact us – we will be happy to put you in touch.


Frequently asked questions concerning our software modernization