Successful Software Projects Need Requirements Planning

complex project will likely fail without a plan. For an architect who wants to build a skyscraper, that plan is a blueprint. For a software developer who wants to satisfy customers’ needs, that plan is a complete, consistent, and correct expression of the stakeholders’ requirements. We must understand a problem before we can express the requirements for a correct solution. Otherwise, we will develop software that fails to provide customer satisfaction, that remains on the shelf rather than off. Expressing a set of complete, consistent, and correct requirements is conceptually complex, but essential in our quest to develop high-quality, useful software. Although small projects can succeed without formal requirements engineering, any project of considerable size and complexity requires it. According to the Standish Group’s 1995 CHAOS survey, the top two “project impaired” factors were incomplete requirements and lack of user involvement. The top three “project challenged” factors in software projects were lack of user involvement, incomplete requirements and specifications, and changing requirements and specifications. Experts that the Standish Group surveyed estimated that bad requirements cause 40 to 60 percent of software defects and failures. The landscape does not appear to be improving much. The Standish Group’s 2000 CHAOS Report— covering a six-year period, 1994–2000— reveals that the majority of software projects (72 percent) still fail. Clearly, we are facing a requirements engineering crisis. A few key principles can help eliminate defects during requirements planning: Understand the problem before expressing the requirements. Before rushing to implement the solution you think your customer wants, be sure you understand the problem. Don Gause once asked attendees at a tutorial to design a transportation vehicle. We were eager to demonstrate our ingenuity and creativity, designing various vehicles such as skateboards, bicycles, boats, and Star Trek transporters, when all he needed was a vehicle to climb an icecoated mountain. We specified the solution before understanding the problem! point