Upgrading Legacy Systems: Don’t Migrate – Convert!

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If you have a legacy system that is running on an ageing platform then sooner or later you will have to consider bringing it up to date. There are problems of maintenance and trying to add facilities such as Web Services or fit them into today’s drive for Service Oriented Architectures. Basically, if you are in this situation you know that you have a problem. There is, of course, always the option of re-writing the entire system. This is painful and expensive but nevertheless it is an option. Normally, this is only appropriate if a company’s requirements for its system have changed out of all recognition since it was first installed.

The second option is to use some of the migration tools that are on the market and upgrade to a modern system. This allows the company to continue using the original code and hardware and so keep continuity. However, once the platform has been upgraded, it is possible to add new services and facilities. There are many excellent products on the market and these shall shortly be the subject of a Bloor report.

Today, however, I am looking at a third option. This is to transform your system rather than migrate it. This comes under the category of getting someone else to re-write your system. More to the point, it is getting a computer to do the re-write for you. The advantages of an automated transformation are that it is quick and you can be confident that the converted system has the same functionality as the original.

Recently I spoke to Northdoor, who are a British company providing a range of IT services. Essentially, they act as an IT Systems Manager for their customers. They have come up against the problem of ageing systems many times. Their solution is to use the Metex Inc’s transformation package.

This package takes code written using Centura, PowerBuilder, RPG, Delphi or Oracle Forms and converts it to Java or .NET. The result is a system that looks and feels like the original but which has the capability to accept upgrades and modern features. By transforming rather than migrating, the intention is to produce program code that is tailored to the new system. The result is a brand new system written in a new language. So if you are converting to Java, you end up with Java code written according to good Java standards. You do not just get your old code with a Java wrapper.

Northdoor became associated with Metex because they had a problem. They were looking after a legacy system and needed to write new programs. It started to get expensive and they were not happy with the results. Having transformed the software they found that their maintenance problems were eased. Subsequently, Northdoor have upgraded a number of their customers and they now provide this as a standalone fixed price service for companies that look after their own computers.

The procedure is that the current system is examined. Northdoor have a policy of checking that the application is appropriate for the business. After all, there is little point in upgrading a system if the problem is that the application is wrong rather than just being out of date. The application is then checked with a polishing tool to get rid of all the little niggles that could become problems. At this point the automated transformation tool is used. Finally, unit and functional testing must check that nothing has been missed.

Transforming a legacy system into a modern system is not instantaneous and it is not painless. However, doing nothing is not a long-term option. Modern ways of working demand that distributed processing, allied with Web Services, must be implemented. Experience suggests that the use of automated tools actually improves the quality of the application. Not, I hasten to add, by the tools themselves but by the polishing that must be done to prepare the code and the testing that is done afterwards.

Although the transformation is a single event it is essential that it be seen in context. Modern systems are designed to change-that is one of their main virtues. So although you can use this tool and Northdoor’s transformation service as the major step in modernising your system, it will only give you full benefit if followed up by regular reviews of the system. Providing System Managers bear this in mind, I have no hesitation in recommending this methodology.