Farewell to waterfalls? - rapid application development - includes product directory

Software Magazine, May, 1995 by Mary Hanna

RAD, said Phelan, is a whole new way of developing systems. "Our RAD procedures include the use of prototyping and running pseudocode. We also step the end user through the application in order to finalize the user interface and the navigational paths before any time has been spent coding." Adage uses CA-OpenRoad, a graphical tool from Computer Associates (CA) International Inc., Islandia, N.Y., for Windows GUI development. CA-OpenRoad, said Phelan, offers a database driver that can link to Oracle, Sybase, Microsoft SQL Server and CA-Ingres databases. Adage has developed its own data modeling tools for back-end development.

As at Adage, specification documentation remains important for HBO and Co., an Atlanta-based healthcare systems provider. RAD practitioners often neglect to document system requirements, said John Crawford, executive director in HBO's research and development organization. "Documenting the requirements is important in order to know when a system is completed and then how to test it properly," Crawford said.

HBO is using RAD techniques to develop a missioncritical system that automates patient admission, identifies procedures covered by insurance, and bills patients.

"Often [system] requirements are not well-known," said Crawford. "When this situation arises, we do quick prototypes using VisualWorks from ParcPlace [Systems Inc., Sunnyvale, Calif.]. The user can decide very quickly what functions must be provided in the system."

Easy Pieces?

Not everyone, however, thinks RAD is appropriate for all phases of the development life cycle. Some developers believe that software assembled from pieces -- not designed as a whole -- will have significant problems. One is George Cagliuso, chief executive officer and founder of Visible Systems Corp., a business process consulting firm in Waltham, Mass.

"The cost of getting requirements is high and it is essential to get them before coding takes place," said Cagliuso. "RAD will work only if the analysis and design work has already been done."

Philip Fasone, president of PowerSolv Corp., a consultancy in Norcross, Ga., agrees. "Despite RAD's high levels of user involvement, developers are still making the same mistakes they did years ago. They jump into coding without sufficient analysis and design. They end up building systems that don't match what the user wants." The RAD approach, he said, can be successful for smaller systems that are two or three screens deep.

Despite the RAD shortcomings he cites, Fasone does not recommend going back to the waterfall method for complex applications demanding significant analysis and design. Instead, his consultancy implements the client/server and RAD methodologies supported by Houston-based LBMS Inc.'s Systems Engineer product. "SE's Client/Server Life Cycle is a robust methodology that includes the user as part of the development team. Because the analysis and modeling are done first, the coding can be accomplished quickly," said Fasone.

PowerSolv uses Powersoft's PowerBuilder for GUI development. LBMS's SE/Open for PowerBuilder allows a bidirectional exchange of design objects between LBMS Systems Engineer and PowerBuilder, said Fasone.