Introduction

Modernizing iSeries (AS/400) applications very often means replacing the aged 5250 presentation with some more modern presentation based on Personal Computer graphic interface.

In general, two main roads are available for modernization:

• New WEB development tools
  • Usually they are based on totally different development methods, require investments in new software, HW enhancements, and new skills development
  • While supporting the development of new WEB applications, usually they cannot be used to migrate to WEB the existing 5250 applications (legacy code).
  • Usually they provide a complete WEB look and feel appearance.
• 5250 to WEB migration tools
  • Used for converting to the WEB the existing 5250 applications (legacy code).
  • The time neeed to perform conversion, the conversion resolution, and the look and feel of the converted pages may significantly change from one product to another one.
  • Some products do not require any new learning at all, while other require the learning of some new language.
  • Some conversion tools would require significant investments in HW enhancements in order to provide adequate performance.

In most cases, an iSeries shop grown through the years will have to consider both these two roads.

New applications may need to be developed with a look and feel completely different from the 5250 tradition. This will require an adequate management decision as to the available development tools. The decision should not only concentrate on the potential final results, it should consider as well the investments in new skills and in HW & SW. Usually, the investments in new skills are by far the most demanding both in terms of time and money.

The effort needed to re-design and re-code the existing applications (legacy code) using new WEB development methods may not result to something affordable, both in terms of timing and of human resources. In these cases, usually the "Conversion Tool" road looks more attractive. Results are usually available in shorter times, though the 5250 translated presentation may often seem an hybrid between the old and the new skins, and may not totally satisfy expert WEB consumers.
The selection of the Conversion Tool requires, however, some degree of attention. Looking only at the appearance of the final result maybe a mistake. Relevant questions to be asked about a Conversion Tool are:

• How much time would is take to master the Conversion Tool?

• Is there some new language typical of the tool to be learned?

• How much manual effort is needed to convert an application program?

• How does the Conversion Tool support application maintenance?

• How about the look and feel of the primitive converted pages?

• What is the effort required to enhance the look and feel of the primitive converted pages?

• How much bandwidth should be added to the existing iSeries?

• The limit of screen scraper technologies
• The complexity and cost of re-writing RPG applications
• The cost and time to wait for Webshpere technology
• The need retain the investment in RPG applications and give RPG programmers an easy route to modernise their applications