NASA's TReK project: a case study in using the spiral model of software development

Software development projects face numerous challenges that threaten their successful completion. Whether it is not enough money, too little time, or a case of "requirements creep" that turns into a full sprint, projects must meet these challenges or face possible disastrous consequences. The funds needed to purchase supporting software tools or computing hardware may not be available, or they may be available for so short a period that informed purchase decisions become infeasible. Personnel resources are often limited, and it is difficult to adjust to personnel fluctuations during the project. The composition of the team personnel also offers potential challenges. A new software development team may begin with some members unfamiliar with the software development environment and project tools, and their learning curve can affect early productivity.