Date of Award


Document Type


Degree Name

Master of Science (MS)

Legacy Department

Mechanical Engineering

Committee Chair/Advisor


Committee Member


Committee Member


Committee Member



This thesis reports a protocol study that examines how designers construct function structure graphs as they understand and develop solutions for novel design problems. Eight voluntary design engineers, with two to four years of experience in product design and function modeling are presented with a novel design problem for which they have to develop functional models as part of concept development. The modeling actions are video recorded and the data is analyzed using a predefined protocol that encodes the addition, deletion, and modification of model elements such as functions, flows, and text, and also other activities such as reading the problem statement and pausing between activities. The protocol is shown to be complete within the scope of the study and the coding scheme is validated with inter-coder reliability analysis. The protocol analysis reveals patterns of occurrences of pauses in the modeling activity, elemental patterns such as Edge- Edge Text (E-ET), Block-Block Text (B-BT) which could help in understanding the designer’s behavior and modeling activities, such as chaining of the model. In aggregate, these observations provide insight into designers' thinking patterns while exploring solutions to unseen problems using function structures. There is suggestive evidence indicating that designers perceive functions as more concrete concepts as opposed to flows. This claim is further strengthened by inspecting the occurrence of the elemental patterns which showed the occurrence of Block-Block Text (B-BT) pattern is higher than the occurrence of Edge-Edge Text (E-ET) pattern. Further, analysis was conducted on the occurrences of pauses before and after the elements, edge, and block showing that the average duration of pause before inserting an edge is the largest while, the average duration of pause after a block is the largest. This thesis also suggests that the designers tend use more of forward chaining and nucleation in the modeling process when compared to backward chaining, for a novel design problem.

Included in

Engineering Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.