For a number of years, firms have been implementing changes in the way they develop new products, changes that are targeted at reducing overall product development cycle times. And over the years, a number of academics have conducted research trying to understand the factors that are related to reducing new product development (NPD) times. But the question remains - just how long does product development generally take in absolute numbers? Information on how long product development takes is helpful to firms for planning and controlling the flow of products into the marketplace and in determining resource needs for NPD. Other than anecdotal data pertaining to particular projects that have been commercialized by particular firms, very little hard data have been reported on this topic. This article analyzes data to quantify average cycle times for physical goods commercialized by business-to-business (B2B) firms. The data are a subset of a much larger data set from the Product Development & Management Association's (PDMA) Best Practices research. The analysis presents average product development cycle times for four different types of projects (new-to-the-world, new-to-the-firm, next generation improvements and incremental improvements), presents evidence of the lack of a relationship between cycle time and success and looks at factors that are associated with differences in the length of product development cycle times. (C) 2002 Elsevier Science Inc. All rights reserved.