Design Decision-making Process Research Articles

B-FMEA-TRIZ model for scheme decision in conceptual product design: A study on upper-limb hemiplegia rehabilitation exoskeleton

Upper-limb rehabilitation devices are essential in restoring and improving the motor function of hemiplegic patients. However, developing a product design that meets the needs of users is challenging. Current design tools and methods suffer from limitations such as a single model, poor synergy between integrated models, and subjective bias in analysing user needs and translating them into product attributes. To address these issues, this study proposes a new structural design decision-making model based on Behaviour Analysis (B), Failure Mode Effect Analysis (FMEA), and Teoriya Resheniya Izobreatatelskikh Zadatch (TRIZ theory). The model was developed and applied to design an upper-limb rehabilitation exoskeleton for hemiplegia. In this paper, an empirical investigation was conducted in several rehabilitation hospitals in Xuzhou City and used user journey mapping to identify potential failure points in the behaviour process. Then, the fault models were ranked according to the Fuzzy Risk Priority Number (FRPN) calculated by FMEA and used TRIZ theory to determine principles for resolving contradictions and generating creative design solutions for the product. By integrating B, FMEA, and TRIZ theory, it eliminated subjective bias in product design, improved the design decision-making process, and provided new methods and ideas for designing assistive rehabilitation devices and similar products. The framework of the proposed approach can be used in other contexts to develop effective and precise product designs that meet the needs of users.

Simulation-Based Learning and Argumentation to Promote Informed Design Decision-Making Processes within a First-Year Engineering Technology Course

Analyzing the integration of scientific knowledge to guide decision-making processes supporting design challenges in engineering education is critical. However, effectively engaging in informed design decision-making processes is challenging, particularly in the context of online education. Simulation-based learning can bring authentic design practices to online education, but effective guidance and scaffolding must be provided to learners. Therefore, this research investigates the implications of integrating simulation-based learning with an argumentation framework to guide students in incorporating scientific knowledge into their design decisions, particularly in designing energy-efficient housing. This study took place during online learning due to the COVID-19 pandemic and was implemented within a first-year engineering technology undergraduate course. It aimed to analyze students’ decision-making processes when designing a zero-energy home for a Midwestern city using Aladdin, an integrated CAD/CAE platform that can be used to design a structure and simulate its function within a single system. This study investigates how students informed their decision-making processes in design for energy-efficient homes and the recurring trends in students’ designs related to economic decision making and energy science. The overall results show how cost constraints significantly influenced students’ observation and argumentation processes during their design challenge, highlighting the pivotal role of economic considerations in shaping their decision making. Moreover, the findings underscore the importance of holistic approaches in providing insights into teaching strategies for online learning, particularly in navigating the intersection of scientific and economic factors in design challenges.

Enhancing life cycle product design decision-making processes: Insights from normal accident theory and the satisficing framework

Life Cycle Assessment (LCA), a computational tool for enabling sustainable product design decision making, faces challenges in the interpretation phase, where conclusions are drawn for improvement recommendations. This necessitate the need to incorporate into LCA management-relevant theoretical underpinnings to strengthen decision-making processes. Comparative LCA case studies of lead-based piezoelectric material (lead zirconate titanate – PZT) and lead-free alternatives (potassium sodium niobate – KNN, sodium bismuth titanate – NBT), was employed to demonstrate how two theoretical lenses, namely Normal Accident Theory (NAT) and the Satisficing Framework, are used inductively to enhance decision making regarding unintended consequences in the value chain. By operationalising NAT, which has hitherto focused on the consequences of physical accidents, as a life cycle engineering-based methodology, NAT attributes of interactive complexity and tight coupling was revealed in piezoelectric materials, based on environmental systems’ predictability, observability, and applicability. This led to the introduction of Environmental Impact Accident (EIA) as a new concept, facilitating an early assessment of the associated complexities influencing the sustainability credentials of piezoelectric materials whilst informing mitigation strategies. However, when considering multiple objectives that conflict or trade-off between alternative piezoelectric materials with different environmental and health impacts across the value chain, a conundrum is created but resolved using the Satisficing Framework. The paper concludes by proposing theoretical and practical policy options for incorporating LCA into product life cycle decision making.

Model of IoT design decision-making processes in Flow Based Programming systems

ABSTRACT The aim of the article is to present a model of decision-making processes in the design of flow-based Internet of Things systems. This is an attempt to fill the research gap in the construction of decision-making systems for designing both infrastructure and the application development environment. Therefore, the aim of the article is to show a decision-making model for selecting infrastructure and design environment for the development of IoT systems. In order for these processes to be implemented, it is necessary to use containerization processes and Flow Based Programming systems, both at the stage of system prototyping and its subsequent implementation. The model verification was carried out on the example of design in accordance with the assumptions of the parallel design process model proposed in the article, using the infrastructure as code approach in infrastructure design, the Docker process for creating containers, publisher and subscriber design in Node Red, and Postgress database design.

BIM4EarlyLCA: An interactive visualization approach for early design support based on uncertain LCA results using open BIM

To meet the European climate goals in the building sector, a holistic optimization of embodied greenhouse gas (GHG) emissions using the method of life cycle assessments (LCA) are necessary. The early design stages have high impact on the final performance of the buildings and are characterized by high uncertainty due to the lack of information and not yet taken decisions. Furthermore, most current LCA approaches based on Building Information Models (BIM) require high expertise and experience in both BIM and LCA and do not follow an intuitive visualization approach for other stakeholders and non-experts. This paper presents a novel design-decision-making approach for reducing embodied GHG emissions by interactive, model-based visualizations of uncertain LCA results. The proposed workflow is based on open BIM data formats, such as Industry Foundation Classes (IFC) and BIM Collaboration Format (BCF), and is developed for decision support for non-LCA experts in the early design stages. With the help of a user study, the prototypical implementation is tested by 103 participants with different levels of experience in BIM and LCA based on a case study. We evaluate the proposed approach regarding the support of open BIM data formats, different LCA visualization strategies, and the intuitiveness of different approaches to visualizing uncertain LCA results. The user study results show a broad acceptance and need for open BIM data formats and model-based LCA visualization but less for visualizing uncertainties, which needs further research. In conclusion, this interactive, model-based visualization approach using color coding supports non-LCA experts in the design decision-making process in early design stages.

Synergistic cotreatment of cooling tower blowdown and produced waters: Modeling strategies for a comprehensive wastewater treatment simulation

Cooling tower blowdown from thermoelectric power plants and produced water from hydraulic fracturing may soften when mixed due to the complimentary chemistry of the two wastewaters. The potential benefit of low effort softening warrants the investigation of a cotreatment process concerning these industrial wastewaters. The synergy is expected to lessen chemical demand for softening and further enable sustainable practices such as designing for a zero-liquid discharge (ZLD) process. The treatment process may then provide a treated effluent suitable for use as blowdown makeup. In this study, the feasibility and effectiveness of a cotreatment train is explored through simulation of chemical softening, filtration, reverse osmosis (RO), multi-effect distillation (MED), and electrolysis unit operations within a comprehensive process model. Innovative modeling strategies are necessary to result in a meaningful process model when considering the significant complexity of the water chemistry for this treatment train. Through the methodology described in this work, a feasible process design is presented as a base case for treatment of experimentally characterized blowdown and produced water samples obtained in the northern Appalachian region. Thereafter, the base case also establishes a platform for more detailed process analyses of different scenarios in future work. Detailed descriptions of modeling methodologies, process design decisions, and simulation results are provided as a perspective on comprehensive modeling of multi-technology treatment trains for complex feedwaters. With the results of the cotreatment simulation, it is determined that the total water recovery of the process may serve to completely makeup the blowdown rate and partially make up the evaporative losses of a theoretical thermoelectric plant's water demand. This complete recovery is evaluated to require 18,343.531 kW of a chemical energy equivalent, 1184.971 kW of electricity, and 68,126.291MJh−1 of power plant steam to result in 408.532m3h−1 of treated water effluent at a quality of approximately 0.135gL−1 total dissolved solids for the base case design.

A practical decision process for building façade performance optimization by integrating machine learning and evolutionary algorithms

ABSTRACT With the development of building design parameterization, more and more designers want to explore design options that optimize performance. However, the enormous time and costs that accompany optimization exploration are often beyond the reach of design practices. The application of machine learning in the construction field in recent years has offered potential solutions. Training predictive models through machine learning enables the rapid assessment of built environment performance and thus brings the optimization process closer to reality. In this paper, we mainly developed a process that integrates machine learning predictive model and multi-objective algorithms to achieve rapid evaluation and obtain optimal solutions. Using façade design as a case study, we demonstrate the design decision process with regard to the optimized solutions. The results showed that, through the proposed visual design decision process, designers can easily compare the performance and design appearance of different solutions and make informed decisions. In addition to saving 87% of time compared to the traditional simulation process, the integrated process also introduced the predictive model, which can achieve optimization exploration in one day. These results all demonstrate that the use of an integrated approach boasts considerable time advantages and potential feasibility in design practice.

Architectural criticism: A review of types and context

Given its wide scope, architectural criticism as a discipline has had a long history of discussions and debates over its uses, contexts, methods, and even boundaries. Authors have alluded to its complex and virtually indefinable nature. The term architectural criticism itself is diverse in its usage, as it is used to describe the activities of critics, academic architectural treatises, and the architectural design decision-making process. Beyond its architectural origins, architectural criticism itself also approaches architecture from an interdisciplinary standpoint, often blending and adapting the methods and ideas of other disciplines to architecture. Despite its long history, not too many review papers approach the subject from a broad and general perspective. The majority of previous works have tended to focus on gaps or more specialized matters within the subject area. This thematic review therefore focuses on the amalgamation of existing literature on the nature of architectural criticism. A keyword search, followed by a filter using inclusion criteria from the Google Scholar Database, identified 52 articles. After a review of these articles, only 26 were found useful. This paper synthesizes and discusses the works of different authors in the areas of types and contexts of architectural criticism. The discussions will benefit future studies on the general nature or characteristics of architectural criticism and can be used as a guideline for highlighting and understanding the key issues in architectural criticism. Keywords: Architectural Criticism, Criticism Context, Criticism Types

Lyocell fibre production using NMMO – A simulation-based techno-economic analysis

The demand for man-made cellulosic fibres is expected to grow in the future. One commercially-available concept to supply fibres is Lyocell manufacturing from dissolving wood pulps using N-Methylmorpholine N-oxide (NMMO) as the solvent. The literature qualitatively indicates that NMMO recycling efficiency is a key factor for profitable operation. Process design information and parameter data are however poorly available publicly to illustrate the cost factors. Therefore, systematic techno-economic analysis of a 50 kt/year Lyocell plant was conducted using steady-state process simulation and cost modeling. With the simulation models, the underlying technical process design and modelling decisions, and economic assumptions were studied. NMMO makeup need is an important cost item. The simulated makeup need is very dependent on the design of the solvent recovery system and the vapor-liquid equilibrium thermodynamic model selection. On the other hand, water use, fibre washing process design, and washing model parameterization have relatively lower impact on the cost of production. Raw material cost and capital expenses are most critical cost items when the NMMO recycling efficiency is high.

SYSTEM VALUE ANALYSIS: MODEL AND EXAMPLE

AbstractSystems design, being a socio-technical discipline, is highly affected by available technologies, the global economy, the state of the environment, and social issues. Hence, in recent years, the ultimate objective of design started to shift from best-performance systems to ones providing value to customers, enterprises, and society. This paper presents a holistic concept of system value, equipping the stakeholders participating in the design process with a broad view of this measure. The contribution of this paper includes a proposal for general system value taxonomy, which can be used as a foundation for a comprehensive, case-specific, system value model (SVM). As an all-round perspective of value is possible only when all stakeholders are represented, we suggest deploying the PSI framework for mapping the relevant stakeholders. The system value analysis of Tesla's Model Y electrical vehicle is demonstrated, as a test case for SVM application. We conclude that a detailed analysis of SVM, performed by a carefully chosen group of diverse stakeholders, highlights less conventionally discussed aspects of the system during design decision processes, hence is expected to improve the system's overall value.

CLUSTERING OF SEQUENTIAL CAD MODELLING DATA

AbstractAutomating modelling activities in computer-aided design (CAD) systems is no exception within design automation, one of the current research endeavours aiming to use and transform design-related data in design decision-making processes and the generation and evaluation facilitation of new design solutions. The paper explores the differences between CAD models based on their feature-based CAD modelling sequences that lead to the final models' design. The dataset collected and structured for the study contains more than 1400 CAD models clustered on two levels by using an unsupervised K-means clustering algorithm. The algorithm is performed on the number (total and unique) and the first-order Markov model transition matrices of the CAD modelling operations and their sequential order, respectively. Therefore, three and ten groups (clusters) of CAD models are obtained regarding the level of clustering. The results show that most of the obtained groups are specified by the dominant transition between particular modelling operations. In addition, the study also provides insight into the potential of using feature-based CAD modelling operations' sequences as a first step toward automating the user interaction with the CAD system.

Refining urban design governance: an investigation of the urban design assessment processes in Aotearoa New Zealand

ABSTRACT This article investigates the urban design decision-making processes within Aotearoa New Zealand. It analyses the documents and terminologies in urban design assessments of residential developments and maps the professions that prepare them. It draws data from four cities: Auckland, Tauranga, Wellington, and Christchurch. The findings reveal a core of referenced documentation but uncertainty regarding supplementary documents, a variety of terminologies, and a range of expertise and qualifications of those preparing the assessments. These findings suggest that further guidance and prescribed professional standards are desirable to refine the governance of the urban design sector in Aotearoa New Zealand.

Building Performance Optimization throughout the Design–Decision Process with a Holistic Approach

Building performance optimization throughout the design–decision process has not been well defined, especially in holistic approaches that require multilevel integration. For this, it is essential to ensure coexistence between different analysis programs such as three-dimensional (3D), energy, and computational fluid dynamics (CFD) models that can be applied on a single platform such as building information modeling (BIM). This research aims, first, to define and document a holistic design approach to building performance optimization concerning energy usage by employing the BIM platform and, second, to underline interoperability and data exchange between current technology and commercially available software from different vendors. Therefore, the novelty of this study is to serve a systematic, multiobjective, and multicriterion optimization of building performance with a holistic approach in the BIM platform. The holistic design approach is for a multidisciplinary design process including three stages (conceptual, schematic, and detailed) that cover different optimization criteria (building envelope design, occupants’ comfort conditions, and building’ energy consumption). The proposed method aims to generate, evaluate, develop, and utilize a 3D model during the different design stages concerning the model’s level of details and included information, which underlines the usage of 3D model-related software and sharing data among the design stages. A BIM-based method is developed through the case study of a hypothetical, two-story building (domestic dwelling) by identifying the activities of each design stage. With the implementation of the proposed method, the result shows a predicted energy saving of up to 75%, with a detailed energy analysis placing the building energy performance in the “A” class (annual energy consumption 17,865 kW · h). At last, based on the authors’ experience during the study, it is time- and effort-saving to have interoperability between BIM tools.

Joint Pilot Spacing and Power Optimization Scheme for Nonstationary Wireless Channel: A Deep Reinforcement Learning Approach

Pilot-assisted channel estimation techniques are essential for wireless communication systems. Most studies focus on the estimation algorithms and interpolation techniques. However, the design of pilot pattern is often neglected. In this letter, we propose a joint pilot spacing and power optimization scheme based on deep reinforcement learning (DRL) to address the mismatch problem of pilot configuration for nonstationary wireless channel. First, we model the adaptive pilot design decision-making process as a Markov Decision Process (MDP) to reduce pilot overhead and power loss. Then a deep Q-network (DQN) based learning algorithm is proposed to optimize the spacing and power of pilots so as to maximize estimation performance while reducing system cost. Simulation results show that the performance of the proposed approach is better than conventional pilot configuration algorithms. Moreover, we analyze the key factors that affect the performance of the proposed scheme.

A generalized disjunctive programming model for the optimal design of reverse electrodialysis process for salinity gradient-based power generation

Reverse electrodialysis (RED) is an emerging electro-membrane technology that generates electricity out of salinity differences between two solutions, a renewable source known as salinity gradient energy. Realizing full-scale RED would require more techno-economic and environmental assessments that consider full process design and operational decision space from the RED stack to the entire system. This work presents an optimization model formulated as a Generalized Disjunctive Programming (GDP) problem that incorporates a finite difference RED stack model from our research group to define the cost-optimal process design. The solution to the GDP problem provides the plant topology and the RED units’ working conditions that maximize the net present value of the RED process for given RED stack parameters and site-specific conditions. Our results show that, compared with simulation-based approaches, mathematical programming techniques are efficient and systematic to assist early-stage research and to extract optimal design and operation guidelines for large-scale RED implementation.

An investigation of the design process’s effect on a high-performance building’s actual energy system performance

The design intent and the performance targets of projects may sometimes fail to match a building’s actual post-occupancy performance. The mismatch of intended and actual building performance can be attributed to multifarious reasons. This study focuses on the role of project decisions made during design as one of the reasons of shortfall. The aim of the study is to unveil the design decision-making process of a state-of-the-art research building through the analysis of project’s available set of IDP (Integrated Design Process) documentation. To understand the relationship and correlation between the energy performance gap and the decision-making process of the case building, we investigated the design decisions’ effect on the actual performance. The particular emphasis is on the decisions that were based on assumptions rather than measured actual test data for the proposed innovative building systems. The designed heat recovery system, which was dependent on recovered heat from the neighboring research building, had a significant effect on the building’s poor energy performance. We investigated collected project data from coordination meetings, thoroughly analyzed project documentation, and quantified the building’s actual energy performance data. The analysis of the project information shows the ripple effect of decisions that were made based on assumptions, that triggered shortfalls in the building’s overall actual performance. Our qualitative analysis indicates that the poor system performance during operations was related with the design decisions that were not based on the measurement of the actual performance of the existing systems in the neighboring building. The performance of the heat recovery from the neighboring building as a highly dependent Energy Conservation Measure (ECM) analyzed through collected documents and data. The ambiguity of the available heat potential from the neighboring building and related testing issues defined on an explanatory timeline of process coding. The conclusion includes recommendations for the design decision-making process for innovative system integrations for high-performance buildings, and underlines the importance of IDP for complex buildings.

Towards net-zero compatible hydrogen from steam reformation – Techno-economic analysis of process design options

Increased consumption of low-carbon hydrogen is prominent in the decarbonisation strategies of many jurisdictions. Yet prior studies assessing the current most prevalent production method, steam reformation of natural gas (SRNG), have not sufficiently evaluated how process design decisions affect life cycle greenhouse gas (GHG) emissions. This techno-economic case study assesses cradle-to-gate emissions of hydrogen produced from SRNG with CO2 capture and storage (CCS) in British Columbia, Canada. Four process configurations with amine-based CCS using existing technology and novel process designs are evaluated. We find that cradle-to-gate GHG emission intensity ranges from 0.7 to 2.7 kgCO2e/kgH2 – significantly lower than previous studies of SRNG with CCS and similar to the range of published estimates for hydrogen produced from renewable-powered electrolysis. The levelized cost of hydrogen (LCOH) in this study (US$1.1–1.3/kgH2) is significantly lower than published estimates for renewable-powered electrolysis.

Rose Fitzgerald Kennedy Bridge Over the River Barrow: Design and Construction of a Multispan Extrados Concrete Bridge

The Rose Fitzgerald Kennedy Bridge spans the River Barrow with two 230-m (755-ft) long main spans. It is an extradosed bridge with three towers, and four spans that are supported by cables in addition to several approach spans to complete the 887 m (2,910 ft) length of the whole superstructure. The design paid special attention to landscape integration, durability, and planning requirements. The analysis was required to address challenges related to structural efficiency under service loads and local code considerations, wind effects on traffic, ship collisions, and fire events analysis as well as construction issues related to the extreme slenderness of the superstructure. The design decision-making process and value engineering were heavily constrained by the contract requirements, which led to a solution that slightly departed from pure engineering optimization but that allowed for the addressing of local requirements and integration with the surroundings. This paper presents a case in which engineers had to comply with specifications set by the Administration, which did not correspond to optimum economic engineering solutions. Other criteria such as the aesthetics or ensuring minimum disruption to the landscape are also valuable, especially in the long term, and may drive engineers to nonstandard proposals.

Amplifying children’s voices: Sustainable Development Goals and inclusive design for education and health architecture

Purpose This scoping review advocates for integrated approaches to the architectural design of education and health environments for children and young people, driven by diverse stakeholder perspectives. Result Limited empirical research specifically focuses on children and young people’s direct involvement in architectural design decision-making processes. Few studies specifically include those experiencing communication disability, or articulate universal strategies to facilitate accessible consultation processes. Despite international agreement of the importance of children and young people’s participation in decision-making (e.g. Sustainable Development Goals [SDGs]), there is limited application in architectural design consultation. Development of consistent guidance supporting inclusive, accessible co-design processes for all potential users and decision-makers is crucial. Conclusion It is necessary to integrate perspectives of those habitually marginalised or excluded from consultation processes, including children experiencing communication disability or with alternative communicative preferences. Doing so amplifies the imperatives articulated in the SDGs, specifically those relating to inclusivity and representativeness in decision-making (SDG 16.7), and designing and building inclusive, safe, child and disability-friendly environments (SDG 4a). This article addresses good health and well-being (SDG 3); quality education (SDG 4); sustainable cities and communities (SDG 11); peace, justice and strong institutions (SDG 16).

Participatory Design

Participatory design is the involvement of people in the creation and management of their built and natural environments. Its strengths are that it cuts across traditional professional boundaries and cultures. The activity of participatory design is based on the principle that the built and natural environments work better if citizens are active and involved in its creation and management instead of being treated as passive consumers. The main purposes of participation are to involve citizens in planning and design decision-making processes and, as a result increase their trust and confidence in organizations, making it more likely that they will work within established systems when seeking solutions to problems; to provide citizens with a voice in planning, design and decision-making in order to improve plans, decisions, service delivery, and overall quality of the environment; and to promote a sense of community by bringing people together who share common goals. A wide range of techniques is available to designers. Some of these techniques have become a standard method used in participatory processes, such as interactive group decision-making techniques that take place in workshops. At the same time, designers have effectively used field techniques such as questionnaires, interviewing, focus groups and group mapping to acquire information. In general, many of the techniques facilitate citizen’s awareness to environmental situations, and help activate their creative thinking. The techniques can be classified as awareness methods, group interaction methods, and indirect methods.