Category: Publication

A new research article co-authored by Hao Chen and Koki Ho (Georgia Tech) and Brian Gardner and Paul Grogan appears in Journal of Spacecraft and Rockets as an “article in advance” manuscript.

Flexibility Management for Space Logistics via Decision Rules

This paper develops a flexibility management framework for space logistics mission planning under uncertainty through decision rules and multistage stochastic programming. It aims to add built-in flexibility to space architectures in the phase of early-stage mission planning. The proposed framework integrates the decision rule formulation into a network-based space logistics optimization formulation model. It can output a series of decision rules and generate a Pareto front between the expected mission cost (i.e., initial mass in low Earth orbit) and the expected mission performance (i.e., effective crew operating time), considering the uncertainty in the environment and mission demands. The generated decision rules and the Pareto front plot can help decision makers create implementable
policies immediately when uncertainty events occur during space missions. An example mission case study about space station resupply under rocket launch delay uncertainty is established to demonstrate the value of the proposed framework.

A new research article authored by Paul Grogan appears in Systems Engineering as an early access manuscript today.

Perception of Complexity in Engineering Design

This paper evaluates perception of complexity in a novel explanatory model that relates product performance and engineering effort. Complexity is an intermediate factor with two facets: it enables desired product performance but also requires effort to achieve. Three causal mechanisms explain how exponential growth bias, excess complexity, and differential perception lead to effort overruns. Secondary data from a human subject experiment validates the existence of perception of complexity as a context-dependent factor that influences required design effort. A two-level mixed effects regression model quantifies differences in perception among 40 design groups. Results summarize how perception of complexity may contribute to effort overruns and outline future work to further validate the explanatory model and causal mechanisms.

A new research article authored by Joseph Thekinen and Paul Grogan appears in Journal of Computing and Information Science in Engineering as an accepted manuscript this month.

Information Exchange Patterns in Digital Engineering: An Observational Study Using Web-Based Virtual Design Studio

This paper performs an observational human subjects study to investigate how design teams use an information system to exchange, store, and synthesize information in an engineering design task. Framed through the lens of decision-based design, a surrogate design task models an aircraft design problem with 12 design parameters across four roles and six system-level functional requirements. A virtual design studio provides a browser-based interface for four participants in a 30-minute design session. Data collected across 10 design sessions provides process factors about communication patterns and outcome factors about the resulting design. Correlation analysis shows a positive relationship between design iteration and outcome performance but a negative relationship between chat messages and outcome performance. Discussion explains how advances in information exchange, storage, and synthesis can support future design activities.

A new research article authored by Ambrosio Valencia-Romero and Paul Grogan appears in Journal of Mechanical Design as an accepted manuscript today.

Structured to Succeed?: Strategy Dynamics in Engineering Systems Design and their Effect on Collective Performance

Strategy dynamics are hypothesized to be a fundamental factor that influences interactive decision-making activities among autonomous design actors. The objective of this research is to understand how strategy dynamics in characteristic engineering design problems influence cooperative behaviors and collective efficiency for pairs of design actors. Using a bi-level model of collective decision processes based on design optimization and strategy selection, we formulate a series of two-actor parameter design tasks that exhibit four strategy dynamics (harmony, coexistence, bistability, and defection), associated with low and high levels of structural fear and greed. In these tasks, actors work collectively to maximize their individual values while managing the trade-offs between aligning with or deviating from a cooperative collective strategy. Results from a human-subject design experiment indicate cognizant actors generally follow normative predictions for some strategy dynamics (harmony and coexistence) but not strictly for others (bistability and defection). Cumulative link model regression analysis shows a greed factor contributing to strategy dynamics has a stronger effect on collective efficiency and equality of individual outcomes compared to a fear factor. Results of this study establish a foundation for future work to study strategic decision-making in engineering design problems and enable new methods and processes to mitigate potential unfavorable effects of their underlying strategy dynamics through social constructs or mechanism design.

On August 17, 2020 Alkim Avsar presented her paper titled “Effects of Locus of Control Personality Trait on Team Performance in Cooperative Engineering Design Tasks” for the 32nd International Conference on Design Theory and Methodology (DTM) at the 2020 ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference (IDETC-CIE). Check it out below!

A new paper authored by Paul Grogan appears on the arXiv pre-print server.

Co-design and Co-simulation for Engineering Systems: Insights from the Sustainable Infrastructure Planning Game

This paper draws on perspectives from co-design as an integrative and collaborative design activity and co-simulation as a supporting information system to advance engineering design methods for problems of societal significance. Design and implementation of the Sustainable Infrastructure Planning Game provides a prototypical co-design platform that leverages the High Level Architecture co-simulation standard. Three role players create a strategic infrastructure plan for agriculture, water, and energy sectors to meet sustainability objectives for a growing and urbaninzing population in a fictional desert nation. An observational human subject study conducts 15 co-design sessions to understand how information system features influence design outcomes. Results show co-simulation facilitates information exchange critical for discovering and addressing interdependencies across role-specific objectives and frequent data exchange is correlated with achieving joint objectives, highlighting the role of co-simulation in co-design settings. Conclusions reflect on the opportunities and challenges presented by co-simulation in co-design settings to address engineering problems for infrastructure systems and more broadly.

A new communication co-authored by Zoe Szajnfarber, Paul Grogan, Jitesh Panchal, and Erica Gralla appears online for Systems Engineering.

A call for consensus on the use of representative model worlds in systems engineering and design

Systems engineering and design (SE&D) researchers increasingly tackle questions at the intersection of technical and social aspects of complex systems design. Practical challenges of access, limited observation scope, and long timescales limit empirical study of SE&D phenomena. As a result, studies are typically conducted in model world settings abstracted from the real world, such as behavioral experiments with student subjects. Model worlds must be representative of the phenomena being studied to ensure insights generalize to the real‐world settings. Currently, there is a lack of shared understanding and standards within the SE&D research community to evaluate representativeness of model worlds. This communication captures the results of ongoing efforts to build consensus on this topic: it defines the concept of model worlds, disambiguates representativeness from related concepts, and draws comparisons to other research domains. It outlines a potential path forward and calls for community participation in establishing shared standards for model world representativeness in SE&D research.

A new article co-authored by Abbas Ehsanfar and Paul Grogan appears online for Journal of Network and Systems Management.

Auction-Based Algorithms for Routing and Task Scheduling in Federated Networks

This paper studies and develops multiple auction-based algorithms for resource exchange among decentralized systems in federated networks with distributed computational resources. Decentralized resource owners and users use processing, storage, and communication units to perform the available computational tasks at each time step while an auctioneer facilitates allocating resources. The auctioneer communicates with federates and receives bids for buying and selling resources, solves combinatorial problems, and proposes prices to federates. Multiple auction-based mechanisms are formulated and assessed using collective performance metrics in a networked federation. The auction-based algorithms include four reverse-bid and double-sided auctions: (1) first-price auction, (2) sequential non-linear pricing auction, (3) min–max closed-form pricing auction, and (4) balanced and maximizing closed-form pricing auction. For results, we assess algorithms for economic and computational efficiency using extensive simulation runs in hundreds of network topologies and initial conditions. The metrics introduced for our numerical validation include normalized bids and prices, collective values, and convergence rates.

Abbas Ehsanfar and Paul T. Grogan

A new article co-authored by Paul Grogan and Ambrosio Valencia-Romero appears online and open-access for Design Science.

Strategic Risk Dominance in Collective Systems Design

Engineered system architectures leveraging collaboration among multiple actors across organizational boundaries are envisioned to be more flexible, robust, or efficient than independent alternatives but also carry significant downside risks from new interdependencies added between constituents. This paper transitions the concept of risk dominance from equilibrium selection in game theory to engineering design as a strategic measure of collective stability for system of systems. A proposed method characterizes system design as a bi-level problem with two or more asymmetric decision-makers. A measure of risk dominance assesses strategic dynamics with respect to the stability of joint or collaborative architectures relative to independent alternatives using a novel linearization technique to approximate linear incentives among actors. An illustrative example case for an asymmetric three-player design scenario shows how strategic risk dominance can identify and mitigate architectures with unstable risk-reward dynamics.

Paul T. Grogan and Ambrosio Valencia-Romero

Alkim Avsar presented a paper on August 19, 2019 titled “The Effects of Locus of Control and Big Five Personality Traits on Collaborative Engineering Design Tasks with Negotiation ” at the 2019 ASME International Design Engineering Technical Conferences (IDETC) Design Theory and Methodology (DTM) Conference in Anaheim California.

Abstract: Collaborative systems design is a human-centered activity dependent on individual decision-making processes. Personality traits have been found to influence individual behaviors and tendencies to compete or cooperate. This paper investigates the effects of Big Five and Locus of Control personality traits on negotiated outcomes of a simplified collaborative engineering design task. Secondary data includes results from short-form personality inventories and outcomes of pair design tasks. The data includes ten sessions of four participants each, where each participant completes a sequence of 12 pair tasks involving design space exploration and negotiation. Regression analysis shows a statistically-significant relationship between Big Five and Locus of Control and total individual value accumulated across the 12 design tasks. Results show the Big Five, aggregating extraversion, agreeableness, conscientiousness, neuroticism, and intellect/imagination to a single factor, negatively affects individual value and internal Locus of Control positively affects individual value. Future work should consider a dedicated experiment to refine understanding of how personality traits influence collaborative systems design and propose interventions to improve collaborative design processes.