The history of modern project management. Precedence diagramming methods
origins and early development
During the swift evolution of modern project management since its inception in 1958, practitioners and researchers have developed and identified numerous tools, techniques, and processes that have enabled them to help advance the field while simultaneously improving their own performance and understanding of the discipline. This article--written by an engineering researcher who led investigations on project management in the late 1950s--explains the origins and early development of the precedence diagramming method (PDM). In doing so, it describes the author's personal account of developing PDM as part of a facilities engineering project for the United States Navy (USN). It also details the author's subsequent work, which included updating PDM to accommodate field office networks, lecturing about PDM in Africa and throughout South America, and studying Denmark's preference for using precedence diagramming method, also known as blocking and an approach that contrasts the North American for the arrow method.