Computer-Aided Software Engineering or CASE is the technology for automating the software development and maintenance process. Many firms are turning to CASE in hopes of realizing improvement in productivity and system quality. Although expenditures on CASE were reported to be rapidly rising, the performance gains have been very difficult to measure. The empirical results in this article are intended to provide some evidence about (1) the major objective of using CASE, (2) the gains from CASE, (3) the difference in productivity among CASE tools. They are based on an analysis of data collected from 61 software engineers from five corporations who have the experience of using CASE.