• Phil Ly

Modernizing SCOBOL Programs Part 1: The Challenge

Part 1: The Challenge

Why Modernize?

The pace of application modernization initiatives on NonStop has accelerated in the past several years, as more users and organizations have started to consider the importance of NonStop’s strategic values. The objectives of application modernization are to reduce risk, reduce costs, and to increase agility. These objectives align with the priorities of all organizations’ IT management.

Migrating Existing Legacy Programs 

Most discussions on application modernization focus on how to develop new applications on NonStop using new technology, such as Java, SOAP, open source frameworks such as SASH. Yet, one of the most common problems faced by IT management is not about the development of new programs, but rather with the challenge of how to migrate existing legacy programs containing complex business logic to a  new programming platform.

This blog series focuses on this last topic and uses SCOBOL as an example. We show how it is possible to extract business logic from a legacy SCOBOL program and incorporate it in a modern version of the program using a software engineering tool called Blu Age.

The Challenge – Embedded Business Logic


Dealing with programs with business logic

Let’s say that you have SCOBOL programs with business logic that you want to transform into to a web graphical user interface (GUI) application. Here are some of your available options in handling the embedded business logic:

Rewriting


Here are some of the challenges:

  1. There is usually no adequate documentation of the existing code. The only thing available is the source code.

  2. That means someone needs to understand how to read SCOBOL code, and someone else with expertise in the new programming environment to assist in the migration.

  3. SCOBOL programming expertise doesn’t necessarily translate to a clear understanding of the business logic in someone else’s code. In most organizations, chances are that the original coder is no longer available.  In some cases, this could be further complicated by the fact that the program had been modified by multiple developers over the years.

  4. Finally, you must verify that all the functions are rewritten correctly.


Caution: Rewriting by hand sounds easier than it really is.


Language Translator


The HP Pathway/iTS product is an example of this kind of translator product. It reads in the SCOBOL source, and generates equivalent Java applet code that will run in the web browser and communicate with the Pathway TCP. There are other commercially available COBOL translator products and services in the market that work similarly on different COBOL variants on different platforms.

While this sounds good in theory, the result usually falls far short from ideal.

  1. This translator would face all the challenges of human “rewriter” without the human’s intelligence. A translator is a black box to its users, and “tuning” by vendor experts is required to produce a successful translation. SCOBOL programming style changes (e.g. two different programmers’ coding styles) may befuddle the translator, requiring expert vendor intervention to keep things moving.

  2. Most translators can deliver only somewhere between 50%-70% success rate at best, and the result varies depending on the complexity of the original program. The rest requires additional manual tweaking by an expert of the tool and could take a fair amount of time.

  3. Experience with program translators shows they can be brittle. Even if the translated program is functional, most likely the generated source code cannot be maintained manually by a developer.

  4. Translated code usually does not perform well, as the vendor of the translator tool focuses more on delivering an output that functions correctly, without regard to performance


So, what would be a better approach? Read about it in our next blog:

Modernizing SCOBOL Programs Part 2:  Re-engineering using Blu Age


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TIC Software, a New York-based company specializing in software and services that integrate NonStop with the latest technologies, including Web Services, .NET and Java. Prior to founding TIC in 1983, Phil worked for Tandem Computer in technical support and software development.

#NonStop #SCOBOL #TICSoftware #Conversion #BluAge #HPENonStop #NET #Modernization #Java

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