Newsletter December 2021

45 Years Delta ADS

Delta ADS turns 50

Developing software is looking to the future, but sometimes it is good to turn around and look back.
As we did, we discovered that the foundations of our products were made almost half a century ago.

Delta ADS - Review

This year, 2026, we celebrate 50 years of Delta ADS. In this years newsletters we will look back on the history of Delta ADS and reflect on its features that have contributed to its long lasting success.

Half a century ago, programming a computer was a special kind of magic for most people. It also was an individual and very creative process with pen, paper and punch cards. Getting complex programs functioning correctly was a difficult and time-consuming process and came with considerable costs that did not allow for the compiler to be used for error finding.

The use of terminals to write programs was a big improvement in the development process. It provided a better overview of the program logic without having to compile and print a listing first. This overview was limited of course by the maximum of 24 lines a terminal was able to show at the same time. This was not sufficient for complex decisions which gave rise to the first tools to support the programming. Although such tools were available for many programming languages, the main field for these tools was in the area of the most widely used programming language for business applications: COBOL.

1971: The First Idea

In 1971, Dr Reinhold Thurner of Zürich University published about the use of decision tables in the software development which led to DETAB/GT to generate the programming code based on a more abstract definition language . By 1976 DETAB/GT reached 100 installations, the same amount of installations was achieved by its competitor VORELLE².

Generating a complex decision structure for COBOL programs was a great help, especially when keeping in mind that in these days COBOL statements were terminated by a single point and complex decisions could easily run over 24 lines of code. It also showed that effective programming needed more. A major step was not in the use of tools but in the way, programs were structured. In an environment dominated by card readers, tapes and report writers (hard disks were expensive and had only limited capacity), each program depended on the structure of the input and output data. The fact that each programmer used his or her personal style and creativity did not make the maintenance of these programs easy. Some kind of craftmanship and best practices was needed. This led to a number of Structured Programming initiatives. The most widely used was Jackson Structured Programming (JSP)³ that Michael Jackson published in 1975.

At the same time Dr. Thurner launched a generator system that, based on the principles of structured programming, was able to produce much of the needed code. It used an abstract description of the structure of the data, in a language specifically defined for that task. The product was called DELTA⁴. It solved the problem that Dijkstra addressed in 1968. The programmer did not need to program and maintain any GO TO statement, only the generator produced them for the executable program⁵.

Over the years, Delta (later called Delta/ADS) was extended with a number of standard generators for standard functionality in Business Programming. PSD (Program Schema Description) and GRU (Control Break Processing) helped programmers to keep an overview of their programs and to focus on the unique functionality they have to implement while not being bothered by mechanisms needed to implement it.

Platform independence - Thanks to Generators

A major step in the development of Delta ADS was the concept of platform independence by the use of generators and macros. Back in the old days, each mainframe (compiler) had its own deviations of the COBOL standard. A program written for platform A was thus not usable on platform B without changing the source code. Not a big deal if you develop your software inhouse for your own use but it is for a software supplier that wants to install his software on many platforms. The use of the generators and macros in Delta ADS to deal with the platform specific aspects of the implementation meant that a program for many different target platforms could be maintained in one single source code object.

Platform independence did not only benefit software suppliers but after some time many Delta ADS users discovered that this possibility also facilitated a platform migration. The fact that an existing application could be migrated easily to a new platform when using Delta ADS is an important reason why many installations are still actively used, some for over 40 years, and that Delta/ADS is still alive and kicking after 50 years.

“I am pleased that after 50 years, Delta ADS is still being used successfully
for the development and migration of large and complex applications.”
Dr. Reinhold Thurner

The Future - and beyond

Like Delta DETAB, Delta ADS for COBOL and PL/I remains a part of our product portfolio. Over the years an estimated 2+ billion unique lines of code have been generated with our generator system, a number that is still growing each year. Initially, DETAB and Delta ADS were only available for the platforms for which they generated code. Today they are also integrated into modern development environments such as Eclipse or Visual Studio and can generate cross-platform.

As the advantages of this generative approach to software development is still valued by our customers we remain committed to supporting them with our tools. The current release 6 of Delta ADS will certainly not be the last as we will continue to find solutions for the challenges our customers experience in their software development process.

History

Article from Computerwoche, January 10, 1975 - Delta Author Dr. Reinhold Thurner:
"Multifunktionales Generator-System für moderne Software-Technologie: Ein Superding für die Avantgarde"

Sources

¹ Thurner R., "Entscheidungs-Tabellen: Aufbau-Anwendung-Programmierung", VDI- Taschenbuch T33, VDI Verlag, Duesseldorf, 1971.

² Jeweils 100mal installiert:: Vorelle und Detab/GT | Computerwoche, 02.07.1976

³ Jackson, MA (1975), Principles of Program Design, Academic.

⁴ Multifunktionales Generator-System für moderne Software-Technologie: Ein Superding für die Avantgarde | Computerwoche, 10.10.1975

⁵ Dijkstra, Edsger W. (March 1968). "Letters to the editor: Go to statement considered harmful" (PDF). Communications of the ACM. 11 (3): 147–148. doi:10.1145/362929.362947. ISSN 0001-0782. S2CID 17469809.
p. 147, "The unbridled use of the go to statement has as an immediate consequence that it becomes terribly hard to find a meaningful set of coordinates in which to describe the process progress. ... The go to statement as it stands is just too primitive, it is too much an invitation to make a mess of one's program."

AMELIO Logic Discovery - 'Nicholas'-Release

AMELIO Logic Discovery helps you to (re) understand your large and complex COBOL, PL/I and ADS applications. The two new perspectives “KnowledgeBase” and “CallTree” speeds up this process.

KnowledgeBase – Finding instead of Searching

With the KnowledgeBase perspective, you get an overview of all analysed artifacts at the push of a button. You can quickly and safely find the access to the modules that are relevant for your task.

Furthermore,

• You get analysis information on groups of artifacts as well as on each individual artifact
• You will find out which (code) patterns were found and how often, both for the entire application, for groups of artifacts or just individual artifacts
• You can use the comment function to record findings and make them available to others
• With the bookmarks and tags you get the possibility to mark artifacts of particular interest to find them easier
• With intelligent filter functions, you can simply focus on the artifacts that are relevant to the current task
  
  

Query Technology

The new query technology expands the KnowledgeBase perspective and provides you with exactly the modules that are relevant for your task. In addition to the ready-made queries, you can now easily define your own queries with the query builder.

Overview in the Application Network

One question that always recurs is to identify dependencies in the network of artifacts: Who is calling whom and who is being called by whom? AMELIO Logic Discovery provides that too at the push of a button. The new CallTree perspective is the counterpart to the established ProgramTree perspective. For a program, it shows the other programs from which it is called.

And beyond,

• You receive information about the program interfaces, which parameters are expected and which are actually transferred
• Decision tables show you clearly and unambiguously which conditions must be fulfilled to enable a program to be called.
  
  

Ensure the Success of your Project through optimal Application Analysis with AMELIO Logic Discovery

Do you want to (re) understand your application, carry out a migration or modernization project?
Or get rid of technical debt from your applications?

AMELIO Logic Discovery helps you with this and automatically provides all the information you need. Try it.

You can find more information about AMELIO Logic Discovery on our website ... or just contact us directly.

Also read ... 

SVA Mainframe Dayz 2021

SVA Mainframe Dayz 2025

In February 2025, the focus will be on the mainframe again!
A variety of presentations, exciting discussions and, above all, lots of field reports from the world of the mainframe await you on February 18th and 19th, 2025 at the Mainframe Dayz in Wiesbaden.

Delta Software Technology is represented with a lecture. On February 19th, 2025 at 1:10 p.m., Dr. Daniela Schilling presents:

"When the English Dictionary is not enough - Understanding Applications with AMELIO"

Regular maintenance, extensions, clean-ups or modernizations - no matter what the task is, without a thorough understanding of the application there is no chance of success. COBOL language is easy to read, but that alone is not enough to actually understand large and complex applications.
Do you want to know how AMELIO Logic Discovery helps you to regain knowledge about your application by means of automated analyses, abstraction and task-specific views?
Then come to our lecture at the SVA Mainframe Dayz on February 19th in Wiesbaden.

Further information, registration and agenda can be found here: https://www.sva-events.de/event/MainframeDayz2025/

Join us and take the opportunity to exchange ideas with your colleagues and discuss current topics.

Register now!

Review: SVA Mainframe Dayz 2023

In March 2023, the focus will be on the mainframe again!
A variety of presentations, exciting discussions and, above all, lots of field reports from the world of the mainframe await you on March 7th and 8th, 2023 at the Mainframe Dayz in Wiesbaden.

Delta Software Technology is represented with a lecture. On March 7th, 2023 at 1:15 p.m., Dr. Daniela Schilling presents:

"Automated Application Cleanup: Using the Washing Machine for Software"

Be there and take the opportunity to present yourself with your colleagues and to shed light on current topics.

Also read about this:

Review: SVA Mainframe Dayz 2022

From March 9th to 10th, 2022 we were at the SVA Mainframe Dayz 2022 in Wiesbaden, Germany!

Delta Software Technology were present with a booth and presentation. On March 9th, 2022 at 2:30 p.m., Dr. Daniela Schilling:

"Successful Automatic Database Migration at Gothaer: In Time - In Budget - In Scope"

You could not attend? Here you can request the presentation slides.
Only available in German. If you are interested in an English version, please contact us directly.

Review SVA Mainframe Dayz 2021

In a monthly event series, the Mainframe SpeakZ, SVA again gave the mainframe a voice. With a diverse mix of customer presentations, industry news, tool updates, and more, SVA keeps you up to date on all things mainframe.

Delta Software Technology was there with a presentation:

"Application modernisation according to your requirements, parallel to ongoing operation"

Dr. Daniela Schilling (CEO Delta Software Technology) explained sticking points and pitfalls in large modernization projects and showed solutions based on a large project at a leading German insurance company.

Contents

The foundation of business-critical applications has often evolved over decades. During this time, the applications were changed and further developed. New technologies were introduced, partly without completely removing the old technologies.

Modernisations such as clean-up, refactoring, technology exchange and standardisation as well as platform migration are necessary to meet new requirements, improve performance and maintainability, and increase the sustainability of the backend applications.

The documentation of the applications and the knowledge about what was implemented and why it was implemented that way has been lost over time.

• So, how do you regain the required implementation knowledge?
• What do you do with the dependencies?
• What about the risks?
• How do you find all the sticking points?
• How do you organise parallel changes and further development?
• What must be tested?
• How do you securely manage (testing) efforts, costs and risks?
• ...

The solution lies in the precisely targeted analysis prior to a modernisation project, the complete automation of the changes and the flexible organisation of the project processes.

Referencing a large project at a leading German insurance company, we show you how you can safely and reliably carry out a complex modernisation of your applications in parallel to ongoing operation in the mainframe area.

Slides and Recording

You could not attend? Here you can request the presentation slides and watch the recording.
Only available in German. If you are interested in an English version, please contact us directly.

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