Productivity is a major source of competitive advantage but improving productivity requires analysis and productivity is getting more difficult to measure as economies become more knowledge, service, and innovation intensive. In this paper, we will provide an introduction to a powerful productivity analysis tool, Data Envelopment Analysis (DEA). DEA is a flexible tool originally created in the 1970s for examining the relative efficiency of non-profit institutions. Researchers have found many more applications and created numerous extensions to DEA. This paper provides an introduction to DEA, a summary of some of the most important modeling variations, and examples of applications relevant to technology management.