Refacing Legacy Systems

Refacing is a term used to describe the process of enabling legacy applications (usually COBOL) using terminal display protocols (for example, 3270 or 5250) to present a user interface using more modern technology, typically web or GUI. In the usual sense, the term implies that the legacy display programs themselves are to remain unmodified. A typical approach is the use of software tools to generate the user interface descriptions from the display files and the use of server software to translate the user interface at run-time.

First and even second-generation "screen scraping" products gained a bad reputation because of the difficulty of developing and maintaining applications produced with them and because of the poor performance these applications often suffered. Nevertheless, the current generation of refacing methods address these issues and might be useful as part of a solution to certain needs:

• Gaining the additional screen real-estate necessary to accommodate field expansion without having to redesign current screens
• Integrating the current online system into a web portal application to provide the functional breadth necessary for user acceptance
• Escaping the "interactivity tax" -- Additional charges often imposed for operating system support of interactive programs on mainframe hardware

Often, the strategy will be to meet immediate needs so as to buy time for a more fundamental re-engineering strategy. This means that the refacing process must to be relatively quick and inexpensive to be useful.

Articles

Web Enabling Legacy AS/400 & iSeries Applications

An executive overview by NetRoutines Software, LLC that categorizes products and approaches to web enable Series legacy applications. Not an exhaustive list by any means.

iSeries / AS400 FAQ: Screen Scraping, Re-facing, Web Enabling
A FAQ that attempts to define common definitions and terminology. Interesting for its categorization of screen-scraping products according to the point at which the product intercepts the 5250 data stream.
 
Products

Attachmate - Verastream Host Integrator
Uses server-side adapters to access legacy system and a model-driven approach to generating J2EE components with JSP front-ends. See the online documentation for detailed technical information.

BOSaNOVA - Web Suite
5250 display emulation over the web using a Java applet

Jacada - Jacada Interface Server
Uses a server-side adapter, DDS mapping and server-side modeling to generate Java source code or XHTML. Probably one of the best-founded and supported products in this area.

looksoftware - newlook
Allows 5250 display programs to run in iSeries CPW batch mode, intercepts screen payloads and presents browser-based UIs that can be extended.

Profound Logic Software - Genie
 Uses native adapters to translate 5250 data streams to HTML on the fly. A WYSIWYG editor allows customization of the resulting HTML pages.

Seagull Software - LegaSuite GUI
Uses screen metadata to automatically identify screens and map fields, from which developers build host screen definitions.  A host server uses a repository to generate a published interface in XML or !J2EE at runtime.

SST Global - Source Translation Utility
 Translates COBOL/400 to Java and interfaces to IBM WebFacing Tool to map display files to Java and HTML.

IBM - WebSphere Host Access Transformation Services
Uses adapters to surface 5250 display programs in a variety of formats, including HTML or Eclipse RCP GUIs.

IBM - IBM Webfacing Tool
Works with WDSC to convert DDS display file source members to Java source code and JSPs for deployment to WebSphere Application Server. See the red book for detailed technical information.