How to Maximize ROI When Re-Facing Legacy Systems

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by Chris Durand

Over the last few years we have completed a number of “legacy modernization” projects wherein we build a browser-based user-interface for iSeries (AS/400) and 3270-based applications while keeping the business logic in the host application (“re-facing”).  Here are a few things we’ve learned:

Re-facing without Extension is a Waste

The main reason a browser-based interface to an application is useful is because everyone knows how to use a web browser.  If all you are doing in your web interface is converting function keys to clickable links and adding eye-candy, you will struggle to find enough ROI to make it worthwhile.  If you are trying to eliminate costs associated with deploying green screen emulator software to user desktops, you are better off deploying a web-based emulator product instead of beginning a screen re-facing development project.

Extend for the Win

Projects that get a lot out of re-facing radically change the user interface and add functionality to applications that is not possible via the green screen.  Leveraging web technologies like HTML, JavaScript, AJAX and Java servlets lets you focus on the user experience and workflow without the constraints of the green screen.  Need to build a single table of data that used to exist on 5 different screens?  No problem!  Need to pull in data from another system to combine with the host screen data?  Done!

The Holistic Approach for Maximum ROI

Re-facing does have limits.  There is only so much complexity you can add to the re-facing layer before it becomes difficult to maintain.  Often the best way to add major new functionality is to create new host screens that do the number-crunching but work seamlessly with the web technologies to build cutting-edge applications.  For example, enable users to make better decisions by providing relevant graphs and reports with a single click in the application, instead having a nightly batch job send them a recap of what happened… hours after the decisions have already been made.  Doing exciting and useful stuff like this is where IT can have a true business impact.

Don’t Forget the Fundamentals

It is tempting to cut corners on requirements and design when working on re-facing projects.  Don’t.  And “just make it work like the host, only in a web page” doesn’t count as requirements.  Good requirements start with understanding how the host works, including dynamically displayed fields, hidden action codes and function keys, etc.  Consult with the power users of the host application to ensure you understand exactly what the new screen needs to be able to do, and be sure to have adequate test data available to ensure your re-faced screen works correctly with all the edge cases.  For more involved updates, a design document is crucial for planning out what logic goes where and how the re-faced UI will interact with the host.

Re-facing is a useful technology whose flexibility if often underestimated.  Since rewriting an application from scratch is fraught with risk and expense, re-facing can be a valuable alternative for bringing legacy applications up-to-date with current technologies and business processes.  Focus on how the application should work, and choose the right tools to get there.

Author: bridge360blog

Software Changes Everything.... Bridge360 improves and develops custom application software. We specialize in solving complex problems at every phase of the software development lifecycle, removing roadblocks to help our clients’ software and applications reach their full potential in any market. The Bridge360 customer base includes software companies and world technology leaders, leading system integrators, federal and state government agencies, and small to enterprise businesses across the globe. Clients spanning industries from legal to healthcare, automotive to energy, and high tech to high fashion count on us to clear a path for success. Bridge360 was founded in 2001 (as Austin Test) and is headquartered in Austin, Texas with offices in Beijing, China.

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