Shraddha Joshi

A user study of interpretability of engineering design representations

In order to save time and money, designers need to understand the utility of different engineering representations. To this end, designers often rely on past experience to decide which model to construct; yet students without this experience have no help. Interestingly there are noticeable gaps in the research literature with respect to how and when to select representations for engineering design. This paper examines the differences between three types of engineering representations, specifically sketches, drawing packages, and physical prototypes. The amount of information designers can extract, in addition to the correctness and confidence, from these representations is studied. Design reviews of concepts with respect to requirements verification serves as the design task of this investigation. The data from this user study are analysed, using descriptive and non-parametric statistics. The results reveal that designers are more confident and correct in making conclusions about whether a design meets requirements when using high-fidelity representations and physical representations, specifically high-fidelity prototypes. Low-fidelity representations appear to be useful for determining if a design meets functional requirements, but not geometric or manufacturing requirements. The relationship between drawing packages and low-fidelity prototypes is still unclear and thus is an area for further research.

Can a Pre-sketching Activity Improve Idea Generation?

This paper examines the influence of a pre-sketching activity on the quantity and novelty of the design solutions. A controlled experiment is used to investigate the influence of pre-sketching activity on quantity and novelty of the concepts. Two student groups sketched solutions for the same design problem; with one group given a pre-sketch activity before the design problem. Results reveal that this short pre-sketching activity positively affects the novelty of the solutions of the design problem (p-value=0.05 for novel means). Further, while the findings suggest that the pre-sketching activity resulted in more concepts generated, this was not found to be statistically significant (p-value=0.22). Therefore, it is recommended that idea generation methods be augmented with short pre-sketching activities before the sessions.

An experimental study: analyzing requirement type influence on novelty and variety of generated solutions

This paper examines the influence of requirement types on the novelty and variety of generated design solutions as studied through a controlled user study experiment. A controlled group of students was given a burrito folder design problem with no requirements and asked to sketch solutions. Three experimental groups given different requirement treatments were also asked to sketch solutions for the same design problem. The experimental conditions were functional requirements, nonfunctional requirements, and randomly mixed requirements. Analysis of the experimental results reveals that there is a significant difference in novelty means between the nonfunctional requirement and the no-requirements group, with the nonfunctional groups achieving higher novelty scores. In addition, the novelty means between the mixed requirements and no requirements are also significantly different. Therefore having nonfunctional or mixed requirements can positively affect the novelty of the solutions. In terms of variety, there are significant differences in means between the nonfunctional requirement and functional requirement groups as well as the nonfunctional and no-requirements groups. It leads to an inference that only nonfunctional requirements are necessary to increase the variety of design solutions. These findings lead to new future research questions relating to understanding exactly how functionality, in this case functional requirements, influences an engineers thinking.

A Coding Scheme for Analyzing Capstone Design Reports: Problem and Solution Descriptions

It is desirable that the graduating engineering students possess the skills of formulating and solving engineering problems to design solutions that meet the established requirements. However, the current literature has noticeable gaps pertaining to understanding how the formulation of design problems and establishment of requirements affect the final design solution. The ultimate goal of this research is to understand the influence of the level of detail of problem statement and requirements on the level of detail of final solution. In order to accomplish this goal a coding scheme is developed to systematically code the information in the final design reports from capstone design class collected over a period of ten years from 1999 to 2008. The coded information is used to develop mappings between problem statement and final solution. To this end, this paper describes the scheme for systematically coding the problem statement and final design solution.Copyright

Experimental Damage Characterization of Hexagonal Honeycombs Subjected to In-Plane Shear Loading

Experimental study on the damage of hexagonal honeycombs under in–plane shear loading does not appear to be available in the literature. In this paper, shear damage behaviors of five different hexagonal mesostructures are investigated with rapid prototyped polycarbonate (PC) honeycomb coupon samples and proper design of a fixture for shear loading. Effective shear stress-strain curves of PC honeycomb coupons are generated for each shear test and the corresponding local cell wall failure is investigated. Two different failure modes of PC honeycombs were observed primarily depending on the cell wall thickness: The PC honeycombs having a lower cell wall thickness induce the plastic post buckling, resulting in preventing propagation of initial cracks through the cell wall end up with higher plastic load bearing. On the other hand, the failure mode of the honeycombs having a high cell wall thickness is the cell wall fracture by crack propagation through wall without severe buckling.Copyright

Representation: Metrics for Analyzing Sketches — A Critical Survey

Sketches are used in design research experiments by various researchers to draw inferences with respect to creativity, representation use, solution quality, and other research goals. Numerous different metrics, such as quantity, sketch quality, and solution quality, are used by the researchers to analyze sketches. This paper presents a survey of the metrics used in the design research community. Characteristics developed by the authors to evaluate these metrics are used to compare the metrics. Further, an initial attempt to identify a relation between type of research approach and characteristics of the metrics is then reported to test the hypothesis that a mature research field would include canonically accepted metrics for experimental studies. The findings indicate that current literature does not provide any formal definition of metrics that are widely accepted in the community. The findings from correlations indicate a general trend of using objective metrics for qualitative research and subjective metrics for mixed method approach. Ultimately, this work lays the foundation for a more systematic approach to evaluating engineering design sketches through critical selection of metrics.Copyright

Requirements and Data Content Evaluation of Industry In-House Data Management System

This paper presents an industrial case study performed on an in-house developed data management system for an automation firm. This data management system has been in use and evolving over a span of fifteen years. To ensure the system is robust to withstand the future growth of the corporation, a study is done to identify deficiencies that may prohibit efficient large scale data management. Specifically, this case study focused on the means in which project requirements are managed and explored the issues of perceived utility in the system. Two major findings are presented: completion metrics are not consistent or expressive of the actual needs and there is no linking between the activities and the original client requirements. Thus, the results of the study were used to depict the potential vulnerability of such deficiencies.Copyright

REQUIREMENTS EVOLUTION: RELATING FUNCTIONAL AND NON-FUNCTIONAL REQUIREMENT CHANGE ON STUDENT PROJECT SUCCESS

This paper presents findings from a study of the evolution of requirements in eight parallel student semester long design projects. Weekly requirements documents were collected and analyzed for the number of functional and non-functional requirements defined by each team. Trends were compared with end of project performance success. The findings provide suggestive, not definitive, evidence that (a) a higher number of defined requirements predicted higher project success, (b) early functional requirement definition relates to project success, and (c) it is important to continually evolve the requirements throughout the project. A set of guidelines and recommendations are developed.

TRACKING PROJECT HEALTH USING COMPLETENESS AND SPECIFICITY OF REQUIREMENTS: A CASE STUDY

Requirements play a critical role in the design process. Much of the project time is spent eliciting the requirements. However, it is observed that students primarily only consider requirements while evaluating the concepts. This paper presents a case study conducted with senior mechanical engineering design students in a capstone course to begin to understand requirement evolution throughout a project. Data in the form of weekly requirements was collected from four teams working in parallel on the same industry sponsored project. The paper introduces the concepts of completeness and specificity that could allow the use of requirements as a tool for measuring project health. The findings from the case study reveal that the completeness and specificity of requirements increase from initial week to final week. 1. RESEARCH MOTIVATION: NOVICE USE OF REQUIREMENTS

Mapping Problem and Requirements to Final Solution: A Document Analysis of Capstone Design Projects

Formulating and solving engineering problems and designing solutions that meet the established requirements are important skills that graduating engineering students need to possess. However, there are noticeable gaps in the literature with respect to understanding how the formulation of design problems and establishment of requirements affect the final design solution in undergraduate design education. This paper is an initial step to understand the influence of level of detail of problem statement and requirements on the level of detail of final solution in capstone design projects. In doing so, a document analysis of final reports from capstone design class collected over a period of ten years, 1999 to 2008, is conducted. A data compression approach is developed to allow for the mapping of level of detail of problem statement and requirements to the level of detail of final solution. The findings of this research indicate that a low level of detail problem statement and requirements leads to no greater than a medium level of detail in the final solution. A high level of detail of final solution is more likely to result from either a high or medium level of detail of problem statement and requirements. Additionally, it was found that a high level of detail final solution is more likely to result in a high percentage of requirements satisfied. These findings are used to make several recommendations to improve the level of detail of the problem statement and requirements so a high level of detail final solution is developed while satisfying a great number of requirements. This assists in ensuring that students possess the skills needed before entering the professional workforce.Copyright