The Art Of Defining Software Requirements

In its annual survey of why software projects fail, The Standish Group last year said only 54% of the originally defined features are delivered, and nearly half of the delivered functionality isn't used. Often, the problem is rooted in poorly defined requirements, the group reported.

Capturing and translating carefully defined software requirements into code is the goal of Telelogic AB's Doors (Dynamic Object Oriented Requirements System). Telelogic on Monday added a product to its suite, Doors/Analyst 1.2, to capture those requirements and move them into Telelogic TAU Developer to produce code. TAU Developer formerly produced application code in the C language. With the addition, it can also produce code in Java and C++.

The system can build models of requirements in Universal Modeling Language 2.0, an industry standard among modeling-tool vendors. UML 2.0 has added the capability to express business-activity diagrams, interaction-overview diagrams, and component diagrams.

The models, in turn, can be imported into Telelogic's TAU Architect 2.3, where a system architecture that can serve as a foundation for meeting the requirements is crafted.

The final step is to move the models into TAU Developer 2.3, which can design system models based on the requirements and architecture. The final output of Developer is automatically generated C++ or Java code, says Michael Donner, VP of global marketing.

By using the three tools, a requirements analyst or software developer may start with a defined requirement and trace it to the underlying software that was designed to meet it. If something doesn't work as expected for the end user, "traceability goes to work for you" and speeds the remedy, says Andy Gurd, senior project manager for the Telelogic tools.

TAU can be used with major Java development tools, such as Sun Microsystems' Java Studio or the IBM-sponsored open-source workbench, Eclipse. Doors/Analyst 1.2, TAU/Architect 2.3, and TAU/Developer 2.3 will be available on April 30. All three run under Windows 2000 and Windows XP. TAU Architect and Developer also run under Sun's Solaris 8 and Red Hat Enterprise Linux.

Telelogic and IBM's Rational Software unit vie to be the leader in the requirements analysis and system-modeling field. The two are about even in market share, with about 30% each.

The requirements-management space has been deemed so important to reliable software development that Rational has tried to define five levels of requirements management and with metrics for each, calling its approach the Rational Unified Process, said Thomas Murphy of the Meta Group in a research report, "Mastering The Requirements Of Requirements Management."

"Most organizations are continually caught in the trap of unwritten add-ons to projects," he noted. These add-ons are not well defined or documented or described in a way that varies from the structure of the original requirements, such as in a spreadsheet, he noted.

Implementing either Doors or Rational's approach still calls for skilled system analysts who understand the business requirements of a proposed system, Murphy wrote in the report.

"If a project can't get a handle on the basic system requirements," the Standish Group report concluded, "it is doomed to fail."