Monday, 29 June 2009

In praise of integration

Having spent over 20 years developing our products using Gen, it is clear that one of the main benefits is the low cost of maintaining applications developed with Gen. I think that there are many reasons for this, some of which are due to inherent features of Gen and others derive from the methods and standards used by the development project. In my view, a key feature of Gen that contributes to the low cost of maintenance is the integrated nature of the analysis and design tools.

The early marketing of IEF (as Gen was called in the early days) emphasised the integrated nature of the product and IEF was called an i-CASE (integrated Computer Aided Software Engineering) tool to distinguish it from point solution CASE tools. Unfortunately many i-CASE tools were nothing of the sort and few if any came close to delivering the 100% code generation and great success of Gen. This resulted in the CASE / i-CASE market getting a bad name, through little fault of IEF.

However. having chosen the best integrated development tool, shouldn’t a Gen project maximise the benefits of that integration? The trend to only use Gen for the server and batch parts of a project concerns me. Whilst there are undoubtedly situations where Gen is not the best choice for developing the user interface, I suspect that there are others where the choice not to use Gen for the front-end has been a mistake due to the resulting increased cost of development and maintenance.

When the user interface is developed with a separate tool, the interface between the presentation layer (client) and the business logic (server) has to become much more formalised at an early stage in the life-cycle, especially when the client and server parts are developed by separate teams. Even if you are using CBD/SOA or some other development approach that advocates stable, published interfaces, there are still many situations when a rapid, iterative approach to development will benefit from having one person develop the client and its closely coupled servers at the same time and with the same tool.

The goal of 100% code generation and integrated nature of Gen means that there are boundaries to the product's capabilities. Whilst there are features that allow external code (external action blocks, OCX controls, etc.), there are still limitations on what can be accomplished with Gen. The perceived weakness of Gen for developing sophisticated user interfaces has made some Gen projects avoid Gen for the user interface or presentation layer of an application.

A few years ago, I was visiting a long standing Gen user who had used Gen very successfully to develop 3270 and batch applications. I demonstrated GuardIEn to the development manager, and then we went for lunch. He explained that they were now moving to client/server but had decided not to use Gen for the front end because they did not think that you could develop a good front end. I asked him what they were looking for, and his response was that they would like to be able to develop something that looked like GuardIEn! He did not realise that GuardIEn was a Gen developed application with the user interface created using the same Gen design tools that they had decided were inappropriate.

Now, to achieve the sophisticated look and feel of our products with Gen has not been easy. We have had to develop an add-on tool (IETeGUI) and learn how best to achieve the desired results. But is this not the case with any tool? Don’t just take the product out of the box and expect to develop a very sophisticated user interface immediately. It needs quite a bit more work than that – probably more than you would expect. It is not easy to create a great user interface with Gen, but it can and has been done, and in my view, the extra effort is more than compensated for by the significant reduction in development and maintenance effort through the use of an integrated tool with 100% code generation.


Lukisan Kaligrafi said...

Yeah...this is what happened to our project. Front end using Java Stripes and Back end using Gen. Can you print screen the GuardIEn interface?

Lukisan Kaligrafi said...

just to add to my previous comment.....we are using the web generation application

Darius Panahy said...

You can see examples of the GuardIEn interface using the demo on our web site at