Editor: Forrest Shull

voice of evidence n Fraunhofer Center for Experimental Software Engineering, Maryland n fshull@fc-md.umd.edu

What Do We Know about Agile Software Development?
Tore Dybå and Torgeir Dingsøyr, SINTEF gile software development has had a huge impact on how software is developed worldwide. A 2005 survey of the US and Europe, for example, revealed that 14 percent of companies were using agile methods, and 49 percent of the companies aware of agile methods were interested in adopting them.1 We can view agile methods such as Extreme Programming (XP) and Scrum as a reaction to plan-

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based or traditional methods, which emphasize a “rationalized, engineering-based approach,”2 incorporating extensive planning, codified processes, and rigorous reuse.3 In contrast, agile methods address the challenge of an unpredictable world, emphasizing the value competent people and their relationships bring to software development.4 Table 1 summarizes these differences. To clarify the effectiveness of agile methods, we reviewed the agile development literature and conducted a systematic study of what we know empirically about its benefits and limitations.
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IEEE Soft warE Published by the IEEE Computer Society

Three overviews from the first half of this decade describe the state of the art and practice of agile development in terms of lessons learned from applying various agile methods in industry. The first is a literature review from a 2002 VTT Electronics technical report.5 The report discussed the agile development concept in general, then presented experiences with 10 agile methods, and compared them with respect to the development phases they support and developer competence levels they require. The authors concluded that only the Dynamic Systems Development Method and the Rational Unified Process cover all development phases fully, while Scrum mainly covers aspects related to project management. They reported anecdotal evidence that agile