The publication of this book "Project Knowledge Management - Systematic Lea- ing with the Project Comparison Technique" by Erwin v. Wasielewski lls me with a special joy. It is a translation of the author's German book "Projektvergleic- technik" which I edited in 2003 in the GPM Deutsche Gesellschaft fur .. Proje- management e.V. series in Germany. I have closely watched the author's work on Project ComparisonTechnique since his rst publicationin 1978, and I have always admired the analytical exactness of his investigations. Unfortunately, as I have to admit in retrospect, v. Wasielewski's ideas were too far advanced. Maybe the fact that parametric analyseswere rarely used in Germanyalso hinderedthe propagation of the method at the time. Duringthe 1970sand early1980s,there was notalk about projectcharacteristics, project benchmarking, or project evaluation. The only exception was an evaluation model presented by Bruce Baker in 1979 during the world congress in Garmisch- Partenkirchen,but this can hardlybe comparedto the approachin this book.Almost nobody re ected on evaluation of project experiences, although in the USA for several years cost data of completed projects were being used to get parametric estimation equations. A chapter "Project Close-out" did not yet exist, and even later was to be found only in advanced technical literature.