Artificial Intelligence for Engineering Design, Analysis and Manufacturing

Special Issue Articles

Variations in functional decomposition for an existing product: Experimental results

Claudia Eckerta1 c1, Anne Ruckpaula2, Thomas Alinka2 and Albert Albersa2

a1 Design Group, Department of Design, Development, Environment and Materials, The Open University, Milton Keynes, United Kingdom

a2 Institut für Produktentwicklung, Karlsruhe Institute of Technology, Karlsruhe, Germany


This paper describes the findings of an experiment on how different engineers understand notions of function and functional breakdown in the context of design by modification. The experiment was conducted with a homogenous group of 20 design engineers, who had all received the same education. The subjects were asked to analyze how a hydraulic pump works and summarize their understanding in a function tree. The subjects were given either the hydraulic pump itself (with part of its casing removed) or a maintenance drawing that showed a section cut of the pump. This paper shows typical outputs of the designers. It discusses the different notions of function that the subjects had and the differences in the function trees they generated. The paper focuses an eight detailed analyses to show the range of approaches the subjects took.

(Received March 03 2011)

(Accepted October 15 2011)


  • Function Analysis;
  • Individual Differences;
  • Protocol Analysis


c1 Reprint requests to: Claudia Eckert, Design Group, Department of Design, Development, Environment and Materials, Room N2056, Venables Building, The Open University, Milton Keynes MK7 6AA, UK. E-mail: