Nees worked with the "Siemens System 2002" to create aesthetic graphics, such as the graphic ″gravel ″ ("Schotter") in 1968. This artwork is well known and can be seen on the website of the Victoria and Albert Museum, London. When writing the program Nees introduced commands for random numbers, which produced from a designated point on the resulting chaos. This causes the graphic to develop from order to disorder or vice versa, if the graphic is turned through 180 degrees (upside down).