Managing Assumptions during Analysis - Study on successful Approaches of Design Engineers
DS 91: Proceedings of NordDesign 2018, Linköping, Sweden, 14th - 17th August 2018
Year: 2018
Editor: Ekströmer, Philip; Schütte, Simon and Ölvander, Johan
Author: Matthiesen, Sven; Nelius, Thomas
Series: NordDESIGN
Institution: Karlsruhe Institute of Technology
ISBN: 978-91-7685-185-2
Abstract
The analysis of technical systems is the basis for a successful product development. Only a detailed understanding of the design problem allows the synthesis of a successful solution. To synthesize an improved design, the design engineer must mentally relate the system’s function and behavior to the system design –a challenging task where many assumptions arise. We already conducted a preliminary study to identify success factors in the analysis. Based on the findings of this, we have set up the following hypotheses.(H1) A structured verbalization of one's own understanding of a technical system helps to identify gaps and mistakes in the own analysis.(H2) Verifying own assumptions about the function and behavior of a technical system improves the quality of the analysis. To test the hypothesizes we conducted an eye tracking study with two realistic design tasks, representing a functional analysis and a synthesis-driven analysis. Concurrent Think Aloud is used to elicit information on the participants’ thoughts and insights. Eye Tracking is deployed to record the participants’ point of gaze and therefore the area of the design, which the participant is analyzing. The combination of the Eye Tracking data with the transcribed Concurrent Think Aloud allows a detailed examination of the analysis approaches. After the participants finished the tasks, they answered a questionnaire to ascertain their understanding of the assigned problem. Success in the analysis is determined by the use of the participants explanation (functional analysis) and the questionnaire (synthesis-driven analysis). Two groups participated in this study to consider differences in the participants' experience-11 design engineers and 13 mechanical engineering students. (H1) In the results we found no evidence that a structured verbalization of one's own understanding of a technical system helps to identify gaps and mistakes in the own analysis. (H2) We found evidence that verifying assumptions on a system's function and behavior enhances the completeness and correctness of the analysis. Although we also found a few cases, where the verification has led to worse results. It seems to be helpful to make several assumptions and to choose the most likely explanation based on the available facts. A procedure that seems logical but was only used by very few participants
Keywords: Human Behavior in Design, Engineering Design, Functional Analysis, Comprehension Process, Product Design