Understanding Designer Mental Models to Support Computer Directed Analogical Design

Analysis of alternative concepts has a significant impact on design project outcomes, and yet many design teams fail to consider a significantly broad range of conceptual solutions. Within the realm of conceptual design exists a technique called design by analogy (DBA) -- the practice of reapplying old solutions to new problems. DBA mitigates the effort required to generate a large field of candidate concepts by leveraging existing knowledge from a wide variety of domains, making it an attractive approach toward improving design outcomes. Unfortunately, DBA is challenging in the absence of expert knowledge. Designers need computational support in order to effectively identify a large number of high-quality analogical connections across a wide variety of domains. With this challenge in mind, the goal of this dissertation is to improve the body of knowledge regarding computational support for design by analogy. More specifically, this body of work includes five manuscripts. Manuscript 0 presents a review of several function-related design abstractions, including their impacts on education and industry. Manuscript 1 studies analogy retrieval in a novel design context and catalogs the types of abstract similarity (including function) commonly used to form analogies. Manuscript 2 examines a scalable approach to capturing analogy-relevant design knowledge to support large-scale analogy searching. Manuscripts 3 and 4 examine and modify a technique from de novo drug design for quickly indexing and retrieving design analogies. Manuscript 3 examines the domain independence of the technique, and manuscript 4 develops it as a large-scale design analogy search method. The body of work contributes to a greater understanding of (1) the abstractions used by designers during conceptual design, (2) the use of human computation to support conceptual design activities, and (3) large scale solution screening using a variety of mixed design abstractions. This understanding advances the creation of tools that enable designers to consider a wide range of conceptual solutions in spite of lacking domain expertise

Toward a functional failure analysis method of identifying and mitigating spurious system emissions in a system of systems

The article of record as published may be found at https://10.1109/RAMS.2019.8768943International Design Engineering Technical Conferences and Computers and Information in Engineering Conference IDETC/CIE2019Increasingly tight coupling and heavy connectedness in systems of systems (SoS) presents new problems for systems designers and engineers. While the failure of one system within a SoS may produce little collateral damage beyond a loss in SoS capability, a highly interconnected SoS can experience significant damage when one member system fails in an unanticipated way. It is therefore important to develop systems that are "good neighbors" with the other systems in a SoS by failing in ways that do not further degrade a SoS’s ability to complete its mission. This paper presents a method to (1) analyze a system for potential spurious emissions and (2) choose mitigation strategies that provide the best return on investment for the SoS. The method is suited for use during the system architecture phase of the system design process. A functional and flow approach to analyzing spurious emissions and developing mitigation strategies is used in the method. Use of the method may result in a system that causes less SoS damage during a failure event

A Generative Human-in-the-Loop Approach for Conceptual Design Exploration Using Flow Failure Frequency in Functional Models

The article of record as published may be found at https://doi.org/10.1115/1.4042913A challenge systems engineers and designers face when applying system failure risk assessment methods such as probabilistic risk assessment (PRA) during conceptual design is their reliance on historical data and behavioral models. This paper presents a framework for exploring a space of functional models using graph rewriting rules and a qualitative failure simulation framework that presents information in an intuitive manner for human-in-the-loop decision-making and human-guided design. An example is presented wherein a functional model of an electrical power system testbed is iteratively perturbed to generate alternatives. The alternative functional models suggest different approaches to mitigating an emergent system failure vulnerability in the electrical power system’s heat extraction capability. A preferred functional model configuration that has a desirable failure flow distribution can then be identified. The method presented here helps systems designers to better understand where failures propagate through systems and guides modification of systems functional models to adjust the way in which systems fail to have more desirable characteristics.This research is partially supported by the Naval Postgraduate School, the Singapore University of Technology and Design, the Technical University of Denmark, and Oregon State University

Systemizing and Automating the Concept Development Process Based on Product Configuration and User Feedback: Case Study on Automating the Design Process of Creating Concepts for a Kitchen Stand Mixer

Optimizing the development and evaluation of concepts during the design of consumer products through, e.g., topology optimization, often excludes areas associated with user needs (e.g., usability). This paper reports on an exploratory study of developing a system which can create new product concepts based on users’ preferences, requirements, and a clearly defined product structure. The 3D model of the product (structured using top-down design and resilient modeling) was integrated with calculations of the performance of the user needs (performance indicators). Different designs were developed based on design of experiment analyses and optimization analyses of the 3D model of the product (a kitchen stand mixer). The outcome of the analyses was a range of concepts which scored differently in the performance indicators. The best designs (based on Pareto front) were evaluated by six potential customers. Half of the participants preferred the same design, suggesting that this tool can be used to develop a design which a specific customer segment prefers. The process of creating the model and using it for customer interviews contributed a set of qualitative findings to the literature on combining parametric design, customization, and systematic design with user needs

Toward a functional failure analysis method of identifying and mitigating spurious system emissions in a system of systems

The article of record as published may be found at https://10.1109/RAMS.2019.8768943International Design Engineering Technical Conferences and Computers and Information in Engineering Conference IDETC/CIE2019Increasingly tight coupling and heavy connectedness in systems of systems (SoS) presents new problems for systems designers and engineers. While the failure of one system within a SoS may produce little collateral damage beyond a loss in SoS capability, a highly interconnected SoS can experience significant damage when one member system fails in an unanticipated way. It is therefore important to develop systems that are "good neighbors" with the other systems in a SoS by failing in ways that do not further degrade a SoS’s ability to complete its mission. This paper presents a method to (1) analyze a system for potential spurious emissions and (2) choose mitigation strategies that provide the best return on investment for the SoS. The method is suited for use during the system architecture phase of the system design process. A functional and flow approach to analyzing spurious emissions and developing mitigation strategies is used in the method. Use of the method may result in a system that causes less SoS damage during a failure event

Toward a generative human-in-the-loop approach for conceptual design exploration using flow failure frequency in functional models

The article of record as published may be found at http://dx.doi.org/10.1115/DETC2018-85490Proceedings of the ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference IDETC/CIE 2018 August 26-29, 2018, Quebec City, Quebec, CanadaA challenge systems engineers and designers face when applying system failure risk assessment methods such as Probabilistic Risk Assessment (PRA) during conceptual design is their reliance on historical data and behavioral models. This paper presents a framework for exploring a space of functional models using graph rewriting rules and a qualitative failure simulation framework that presents information in an intuitive manner for human-in-the-loop decision-making and human-guided design. An example is presented wherein a functional model of an electrical power system is iteratively perturbed to generate alternatives. The alternative functional models suggest different approaches to mitigating an emergent system failure vulnerability in the electrical power system’s the heat extraction capability. A preferred functional model configuration that has a desirable failure flow distribution can then be identified. The method presented here helps systems designers to better understand where failures propagate through systems and guides modification of systems functional models to adjust the way in which systems fail to have more desirable characteristics.Singapore University of Technology and Design (SUTD).Naval Postgraduate School (NPS

A Functional Failure Analysis Method of Identifying and Mitigating Spurious System Emissions From a System of Interest in a System of Systems

The article of record as published may be found at http://dx.doi.org/10.1115/1.4046991Increasingly tight coupling and heavy connectedness in system of systems (SoS) present new problems for systems’ designers and engineers. While the failure of one system within a loosely coupled SoS may produce little collateral damage beyond a loss in SoS capability, a highly interconnected SoS can experience significant damage when one member system fails in an unanticipated way. It is therefore important to develop systems that are “good neighbors” with the other systems in an SoS by failing in ways that do not further degrade an SoS’s ability to complete its mission. This paper presents a method to (1) analyze a system of interest (SoI) for potentially harmful spurious system emissions (failure flows that exit the SoI’s system boundary and may cause failure initiating events in other systems within the SoS) and (2) choose mitigation strategies that provide the best return on investment for the SoS. The method is intended for use during the system architecture phase of the system design process when functional architectures are being developed, and analysis of alternatives and trade-off studies are being conducted.Naval Postgraduate SchoolTechnical University of Denmar

A method of identifying and analyzing irrational system behavior in a system of systems

The article of record as published may be found at https://10.1002/sys.21520System of interest (SoI) failures can sometimes be traced to an unexpected behavior occurring within another system that is a member of the system of systems (SoS) with the SoI. This article presents a method for use when designing an SoI that helps to analyze an SoS for unexpected behaviors from existing SoS members during the SoI’s conceptual functional modeling phase of system architecture. The concept of irrationality initiators—unanticipated or unexpected failure flows emitted from one system that adversely impact an SoI, which appear to be impossible or irra- tional to engineers developing the new system—is introduced and implemented in a quantitative risk analysis method. The method is implemented in the failure flow identification and propagation framework to yield a probability distribution of failure paths through an SoI in the SoS. An example of a network of autonomous vehicles operating in a partially denied environment is presented to demonstrate the method. The method presented in this paper allows practitioners to more easily identify potential failure paths and prioritize fixing vulnerabilities in an SoI during functional modeling when significant changes can still be made with minimal impact to cost and schedule.This research is partially supported by the Naval Postgraduate School (NPS), the Singapore University of Technology and Design (SUTD),∗ and Danmarks Tekniske Universitet

Irrational System Behavior in a System of Systems

The article of record as published may be found at http://dx.doi.org/10.1109/SYSOSE.2018.8428778Published in: 2018 13th Annual Conference on System of Systems Engineering (SoSE)System of systems (SoS) failures can sometimes be traced to a system within the SoS behaving in unexpected ways. Due to their emergent complexity, these types of failures are notoriously challenging to foresee. This paper presents a method to aid in predicting unknown unknowns in a SoS. Irrationality initiators – failure flows emanating from one system that serve as unexpected initiating events in another system – are introduced into quantitative risk analysis methods such as the Failure Flow Identification and Propagation framework and Probabilistic Risk Assessment. Analysis of models built using this approach yield a probability distribution of failure paths through a system within the SoS that are initiated by unexpected behaviors of other systems within the SoS. The method is demonstrated using an example of an autonomous vehicle network operating in a partially denied environment with hostile forces present. Using the concept of irrationality initiators, it is possible to identify and prioritize vulnerabilities in the system of interest in the SoS.Naval Postgraduate School (NPS)Singapore University of Technology and Design (SUTD