Diagrammatic Abstractions: Jay Forrester’s Urban Dynamics and Its Contribution to Architecture and Urban Planning in the Late 1960s and Early 1970s

In the 1960s and ’70s, Jay Wright Forrester (1918–2016) created a rigorous new method he called Urban Dynamics, in which he applied systems theory to urban planning by an extensive use of diagrams and computation. This article discusses how Forrester’s theories migrated from business theory to urbanism in educational settings and into real-life planning scenarios in the US Department of Housing and Urban Development (HUD). By focusing specifically on how Forrester adopted systems drawings that incorporated data and the use of computation for urban planning, the article argues that Urban Dynamics marked a changing approach to urban planning, favouring general managerial knowledge over competences specific to urban design. By conducting a visual analysis of Forrester’s diagrams, the article demonstrates how Forrester’s diagrams for his Urban Dynamics model were instrumental in concealing political ideals that blurred the border between the real and the ideal.