Observations of designer behaviors in complex system design

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 47-51).The design of large-scale engineering systems requires design teams to balance a complex set of considerations. Formal approaches for optimizing complex system design assume that designers behave in a rational, consistent manner. However, observation of design practice suggests that there are limits to the rationality of designer behavior. This paper explores the gap between complex system designs generated via formal design process and those generated by teams of human designers. Results show that human design teams employed a range of strategies but arrived at suboptimal designs. Analysis of their design histories suggest three possible causes for the human design teams' performance: poorly executed global searches rather than well executed local searches, a focus on optimizing single design parameters, and sequential implementations rather than concurrent optimization strategies.by Jesse Austin-Breneman.S.M

Biased Information Passing Between Subsystems Over Time in Complex System Design

The early stage design of large-scale engineering systems challenges design teams to balance a complex set of considerations. Established structured approaches for optimizing complex system designs offer strategies for achieving optimal solutions, but in practice sub-optimal system-level results are often reached due to factors such as satisficing, ill-defined problems or other project constraints. Twelve sub-system and system-level practitioners at a large aerospace organization were interviewed to understand the ways in which they integrate sub-systems. Responses showed sub-system team members often presented conservative, worst-case scenarios to other sub-systems when negotiating a trade-off as a way of hedging their own future needs. This practice of biased information passing, referred to informally by the practitioners as adding “margins,” is modeled with a series of optimization simulations. Three “bias” conditions were tested: no bias, a constant bias and a bias which decreases with time. Results from the simulations show that biased information passing negatively affects both the number of iterations needed to reach and the Pareto optimality of system-level solutions. Results are also compared to the interview responses and highlight several themes with respect to complex system design practice.National Science Foundation (U.S.). Graduate Research Fellowship Progra

A Study of Student Design Team Behaviors in Complex System Design

Large-scale engineering systems require design teams to balance complex sets of considerations using a wide range of design and decision-making skills. Formal, computational approaches for optimizing complex systems offer strategies for arriving at optimal solutions in situations where system integration and design optimization are well-formulated. However, observation of design practice suggests engineers may be poorly prepared for this type of design. Four graduate student teams completed a distributed, complex system design task. Analysis of the teams' design histories suggests three categories of suboptimal approaches: global rather than local searches, optimizing individual design parameters separately, and sequential rather than concurrent optimization strategies. Teams focused strongly on individual subsystems rather than system-level optimization, and did not use the provided system gradient indicator to understand how changes in individual subsystems impacted the overall system. This suggests the need for curriculum to teach engineering students how to appropriately integrate systems as a whole.National Science Foundation (U.S.) (Award CMMI-0830134)National Science Foundation (U.S.) (Award CMMI-0900255)Ford Foundation (Predoctoral Fellowship

Integrating Audiovisual Immersion Into Pediatric Radiation Therapy Across Multiple Centers: Methodology, Timeliness, and Cost of the Audiovisual-Assisted Therapeutic Ambience in Radiation Therapy Prospective Multi-Institutional Trial.

PURPOSE: The Audiovisual-Assisted Therapeutic Ambience in Radiotherapy (AVATAR) trial was a prospective multicenter study (NCT03991156) examining the combination of video immersion with radiation therapy and was successfully conducted through the collaboration of pediatric radiation oncology teams at 10 institutions independent of any pre-existing consortium. We sought to analyze and report the methodology of trial conception and development, process map, and cost. METHODS AND MATERIALS: The study enrolled patients aged 3 to 10 years preparing to undergo radiation therapy, integrated the combination of AVATAR-based video immersion with radiation therapy at each institution, and offered AVATAR use as an alternative to anesthesia, with rates of anesthesia use and outcomes of serial standardized anxiety and quality-of-life assessments assessed among the 81 children enrolled. A process map was created based on the trial timeline with the following components: study development time (time from conception of the trial to the accrual of the first patient, including design phase, agreement and approval phase, and site preparation phase), and accrual duration time (time from the first to last accrual). Costs and institutional success rates were calculated. RESULTS: Time from inception of study to last accrual was 3.6 years (1313 days). The study development time was 417 days (31.7%), and accrual duration time was 896 days (68.3%), with the final 50% of accrual occurring in <6 months. Equipment cost was approximately $550 per institution and was covered by funding from the lead study institution. All 10 centers were successful with AVATAR implementation, defined as ≥50% of patients able to avoid anesthesia with the use of AVATAR, including centers with both photon and proton therapy. CONCLUSIONS: This report elaborates on the methodology and timeline of trial conception and development using data from a previously published supportive care study combining video immersion with radiation therapy among 10 cooperating pediatric oncology institutions. It highlights the potential for multicenter collaborations on prospective trials integrating supportive care therapies with radiation therapy

Aligning stakeholder interests : from complex systems to emerging markets

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (pages 87-94).Design often requires balancing competing objectives from a variety of stakeholders. From the design of large-scale complex engineering systems to the design of end-user products for emerging markets, managing the trade-offs between different objectives from a systems-level perspective is a key challenge for design teams. This thesis investigates differences between how formal strategies can be used to balance trade-offs and how practitioners currently perform this task. Through the use of interviews, case studies, and field and laboratory experiments, this thesis seeks to examine how real-world designers approach these problems. The work investigates practitioner strategies and analyzes them to gain a better understanding of how human design teams operate. These insights are then used to inform proposed guidelines for performing design tasks in these contexts. First, observations of practitioners in space system design lead to a new way of modeling interactions between sub-systems. Then, interviews with designers working on products for emerging markets are used to formulate a new methodology, Design for Micro-Enterprise, that focuses on the needs of small-scale entrepreneurs. Results from the analysis suggest that focusing on a micro-entrepreneur's business strategy may be a successful approach to balancing both the end-user and supply chain requirements in these markets.by Jesse Austin-Breneman.Ph. D

DESIGN FOR MICRO-ENTERPRISE: AN APPROACH TO PRODUCT DESIGN FOR EMERGING MARKETS

Product design for emerging markets in the developing world is a rapidly growing field due to a steadily increasing market and an interest in profitably transforming consumer quality of life for this population. Economic and cultural barriers as well as other constraints present a daunting challenge for designers working in this area. This study documents current best practices and proposes a framework for future designers with a focus on creating products that foster micro-enterprise. These guidelines are drawn from existing literature and interviews with practicing designers of products for emerging markets. Four case studies are presented ranging across several product categories.

Prototyping methods and constraints for small-to-medium sized enterprises in East Africa

Prototyping is integral to the design process for all projects, but particularly for small and medium-sized enterprises (SMEs). In resource-constrained contexts, designers must operate under unique constraints and opportunities. This study investigates the methods, constraints, and impacts on design outcomes of prototyping in seven design and manufacturing SMEs in East Africa. Results from a site visit to a Rwandan partner company as well as interviews with the engineering teams of the other organizations are presented. Practitioners reported that the main intent of prototyping in this context is to develop functional prototypes with increasing fidelity through a highly iterative process. This process was limited by constraints to manufacturing inputs, capabilities, and modeling predictions. These constraints contributed to increases in the time and cost for each iteration. Thus, results indicate that there may be a mismatch between the highly iterative method chosen and the constraints of the operating context. Keywords: Design for development, Prototypes, Developing countries, Prototyping methods, Design for manufacture, Engineering for global development, Design for the developing worl

Changing Subsystem Information Strategies Using Weighted Objectives: Increasing Robustness to Biased Information Passing

Complex system design requires managing competing objectives between many subsystems. Previous field research has demonstrated that subsystem designers may use biased information passing as a negotiation tactic and thereby reach sub-optimal system-level results due to local optimization behavior. One strategy to combat the focus on local optimization is an incentive structure that promotes system-level optimization. This paper presents a new subsystem incentive structure based on Multi-disciplinary Optimization (MDO) techniques for improving robustness of the design process to such biased information passing strategies. Results from simulations of different utility functions for a test suite of multi-objective problems quantify the system robustness to biased information passing strategies. Results show that incentivizing subsystems with this new weighted structure may decrease the error resulting from biased information passing.University of Alabama in Huntsville. System Engineering ConsortiumNational Science Foundation (U.S.). Graduate Research Fellowshi

How do managers evaluate individual contributions to team production? A theory and empirical test

Research SummaryOrganizations rely on subjective evaluations to reward employees for team-based performance. However, it is unclear how supervisors determine individuals’ contributions to collective output. We theorize that supervisors rely on the covariance between employees’ presence and their teams’ productivity. If teams are more productive when an employee is present, the supervisor may infer a greater contribution from the employee. Using data from a manufacturing firm, we find that covariation between an employee’s presence and her team’s output has a positive effect on her evaluation. This relationship is stronger when supervisors have more opportunities to observe an employee across various teams and when the employee has more authority to direct team production, supporting counterfactual information as an important component of evaluations for individuals engaged in team production.Managerial SummaryIt is notoriously difficult to evaluate the individual performance of employees when the only available metric is team-based output. We suggest that supervisors help solve this problem by observing how team output correlates with changes in team membership. We construct a measure of the covariance between an employee’s presence in a team and the team’s productivity, and find a positive relationship between this measure and the employee’s annual subjective performance evaluation. Our results indicate that subjective evaluations reflect individual contributions to team production fairly well for employees who (a) have sufficient authority to direct team production and (b) are frequently rotated beyond a single team. We discuss what kinds of organizations might benefit from this measure as an input to their performance evaluation processes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/175231/1/smj3433.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175231/2/smj3433_am.pd