Showing papers in "Journal of Engineering Design in 2012"

A review of product–service systems design methodologies

Abstract: Product–service systems (PSS), motivated to fulfil customers’ needs, are seen as good strategies to face today's competitive business environment. The field of PSS research is however not fully mature and many different methodologies are proposed for the PSS design. This paper seeks to understand the directions taken in eight state-of-the-art methodologies so as to identify common needs in future research. The methodologies are studied across their authors’ views and definitions of services, PSS and their objectives and challenges, along with the tools that have been developed. A maturity model is built to access the current PSS design across 20 dimensions. The model highlights that only three dimensions are strongly treated: design processes for integrating products and services, definitions of new terminologies and considerations concerning planning and designing life-cycle phases. To enhance the industrial application, collaboration between researchers and practitioners can be spurred through two chall...

Comparison of the degree of creativity in the design outcomes using different design methods

Abstract: This work analyses the influence of several design methods on the degree of creativity of the design outcome. A design experiment has been carried out in which the participants were divided into four teams of three members, and each team was asked to work applying different design methods. The selected methods were Brainstorming, Functional Analysis, and SCAMPER method. The ‘degree of creativity’ of each design outcome is assessed by means of a questionnaire offered to a number of experts and by means of three different metrics: the metric of Moss, the metric of Sarkar and Chakrabarti, and the evaluation of innovative potential. The three metrics share the property of measuring the creativity as a combination of the degree of novelty and the degree of usefulness. The results show that Brainstorming provides more creative outcomes than when no method is applied, while this is not proved for SCAMPER and Functional Analysis.

Predicting requirement change propagation, using higher order design structure matrices: an industry case study

Abstract: This research examines higher order design structure matrices as requirements change modelling tools to predict requirement change propagation through two large-scale industry design projects. Due to the iterative nature of design, requirements will evolve and change. Changes in requirements can propagate to other requirements on different subsystems leading to possible increases in the project cost and lead-time. Predicting these requirement changes enables the designers to foresee unanticipated changes and maximises the probability for the project's success. These studies reveal that second-order relationships are influential in predicting requirement change propagation. Unforeseen propagation occurring in first-order form was rare, rather it was occurring in second order. Modelling requirements change exposes these secondary relationships early in the engineering change (EC) definition process, thereby enhancing the decision-making process and augmenting cost estimation. A modelling tool, such as that ...

A theoretical analysis of creativity methods in engineering design: casting and improving ASIT within C–K theory

Abstract: Approaches to supporting creativity are diverse and numerous. Making sense of these methods, including the comparative benefits of one approach over another is highly significant to both research and practice of creative design. This paper demonstrates the benefit of conducting analyses of methods with the aid of a theory. Such an approach provides a clear basis for analysing different methods that could in turn be compared with each other. This approach is demonstrated through the critical analysis of advanced systematic inventive thinking (ASIT) – a practical method – using the C–K theory, a design theory that offers a formal model of creative thinking. The analysis uncovers a paradox in ASIT operation: being creative while ‘staying in the box’. While confirming that ASIT could be perceived as an implementation of some of the C–K constructs, the analysis further resolves the paradox by explaining how creative solutions could be created with ASIT. Finally, the analysis also exposes the capabilities and l...

From a conventional to a sustainable engineering design process: different shades of sustainability

Abstract: The challenge of realigning the present path of development on a sustainable trajectory concerns all sectors of society, including engineering. To move towards a sustainable practice of engineering...

A user study of interpretability of engineering design representations

Abstract: 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 re...

Creativity from Constraints in Engineering Design: Lessons Learned at Coloplast

Abstract: This paper investigates the role of constraints in limiting and enhancing creativity in engineering design. Based on a review of literature relating constraints to creativity, the paper presents a longitudinal participatory study from Coloplast A/S, a major international producer of disposable medical equipment. At Coloplast, constraints played a fundamental role and the observations show the important, dual role of constraints in terms of being a limitation and a prerequisite for creativity. Too few or too many constraints had a negative impact on creativity, whereas the formulation, rationale and ownership of formal constraints played a crucial role in defining their influence on creativity – along with the tacit constraints held by the designers. The designers were found to be highly constraint focused, and four main creative strategies for constraint manipulation were observed: blackboxing, removal, introducing and revising. Constraints introduced late in a project contributed to the generation of new...

Comparative analysis of coupling modularity metrics

Abstract: Modular design has become a widely accepted developmental strategy to create products and systems that can be easily manufactured, upgraded and maintained. In order to achieve these benefits through improvement of a system's modularity, it must be measured. An ideal measure ought to capture modularity while being independent of other architectural factors such as size, system coupling density or the number of modules. In this work, we review past research on modularity measures. Eight modularity measures are selected for a detailed analysis. We use a design of experiments approach to analyse which metrics best measure the degree of modularity independent of other irrelevant factors. To do this, we conduct a factorial analysis of 24 canonical architectures with idealised modularity, including precisely integral, modular and bus architectures. We find that most measures produce inconsistent results, especially if the system architecture contains a bus or modules with loose internal coupling. We identify the...

Investigating effects of oppositely related semantic stimuli on design concept creativity

Abstract: We are motivated to investigate methods to increase creativity in conceptual design since creativity is essential to design success, and no other stage influences final design success as much as conceptual design. Existing work supports that design stimuli may encourage creative concept generation, but does not give details on how to systematically generate stimuli. The established relationship between language and cognition, and the systematic nature of language prompt us to examine its use as design stimuli. Language relationships such as opposition provide a systematic method of generating non-obvious semantic stimuli for design problems. In this paper, we present two experiments, a pen-and-paper and a verbal protocol study, where participants used oppositely related and similarly related word stimuli in conceptual design. We found that designers using oppositely related word stimuli developed more creative concepts. Language analysis revealed how opposite stimuli elicited designer behaviours that may ...

Development of design collaboration skills

Abstract: This paper aims to advance our conceptual understanding of design collaboration, a domain-specific subset of collaboration skills that emphasises knowledge-sharing and knowledge-integration processes This paper explores how design collaboration skills develop along with design expertise across three stages of experience First-year bachelor students, master students, and design professionals took part in a design game to investigate their design collaboration skills We assessed their design collaboration skills by analysing their sessions for the degree and quality of knowledge sharing and integration using a reflective practice analysis and an interpretative analysis of their conversation It was found that the first-year bachelor students and the professionals outperformed the master students in terms of collaborative design performance In finding this nonlinear relationship, we highlight the need to distinguish between design expertise and design collaboration skills and to treat them as independent concepts when assessing design team performance Finally, through an interpretive analysis, we developed a typology of design collaboration approaches at the three stages of experience

Modular product development through platform-based design and DFMA

Abstract: This article presents a framework for modular product development by integrating function-based modular product architecture, platform-based design and design for manufacture and assembly. This product development framework facilitates the combined benefit from different product development methodologies to make robust products. It helps in incorporating customer requirements into product architecture. This method may reduce product manufacturing cost and throughput time for product development. Application of the integrated framework is illustrated with a case study of the development of a watch mechanism. The illustration gives light to the stages of product development from conceptual evolution of the product to the detailed design.

Simulation in user-centred design: helping designers to empathise with atypical users

Abstract: Time and budget constraints frequently prevent designers from consulting with end-users while assessing the ease of use of the products they create. This has resulted in solutions that are difficult to use by a wide range of users, especially the growing older adult population and people with different types of impairments. To help designers with this problem, capability-loss simulators have been developed with the aim of temporarily representing users who are otherwise difficult to access. This paper questions the reliability of existing tools in providing designers with meaningful information about the users’ capabilities. Consequently, a new capability-loss simulation toolkit is presented, followed by its empirical evaluation. The new toolkit proved to be significantly helpful for a group of designers identifying real usability problems with everyday devices.

A high-definition design structure matrix (HDDSM) for the quantitative assessment of product architecture

Abstract: As the field of engineering design matures, new techniques and methods are continuously being developed to conceptualise and analyse product architecture. These techniques and methods require product representations with higher sophistication, granularity, and fidelity. To address these needs, the high-definition design structure matrix (HDDSM) is presented as a new and evolved product representation model that captures a spectrum of interactions between components of a product, such that characteristics of product architecture can be assessed and compared. The HDDSM includes an interaction basis to capture a variety of standardised types of interactions and a hierarchical modelling method to facilitate modular, more efficient compilation of a design structure matrix with a high level of detail. To illustrate the types of quantitative analyses supported by the HDDSM, it is used as a foundation for quantifying the degree of nesting and identifying the presence of frameworks in product architectures – two c...

Distributed idea screening in stage–gate development processes

Abstract: This paper investigates the gate screening of ideas in engineering design, by examination of the validity of employee voting schemes and biases associated with such voting. After conducting an employee-driven innovation project at a major producer of disposable medical equipment, 99 ideas had to be screened for further development. Inspired by the concept of ‘wisdom of the crowd’, all ideas were individually rated by a broad selection of employees, and the ratings were used to investigate two biases in employee voting: visual complexity and endowment effect/ownership of ideas. The visual complexity bias was found to be a predictor for selection, but experienced employees were less affected by the bias. The ownership bias was potent in that every employee proved to be more likely to select his or her own ideas over other ideas, but this effect disappeared when aggregating across the crowd of employees. Furthermore, this study compared the employee selection with the preference of a small team of executives...

Newer is better! The influence of a novel appearance on the perceived performance quality of products

Abstract: Understanding how consumers perceive products based on their appearance is of great importance to designers. In this article, we explore the level of novelty of a product appearance as a general design guideline to evoke positive associations about the product's performance quality. Novelty implies the deviation in a product appearance from the current design state. Based on the literature, we theorise that consumers associate products with a novel appearance with technological advancement and thus with a greater performance quality. Data from two studies in which participants were asked to evaluate washing machines and single-lens reflex cameras support our expectations that the level of novelty of a product appearance positively affects the perceived performance quality of the product.

Constructive simulation of creative concept generation process in design: a research method for difficult-to-observe design-thinking processes

Abstract: In this study, we conduct a computer simulation in order to capture characteristics or patterns in the concept generation process, which may lead to the generation of a creative design idea. This approach employs a research framework called ‘constructive simulation’, which may be effective for investigating a process that is difficult to observe both internally and externally. The simulation was conducted in four phases. In Phase 1, the virtual concept generation process was constructed on a semantic network. In Phase 2, the relevance of the process was confirmed using network theory. In Phase 3, the simulation was validated using ‘synthetic verification’ which confirms the relevance of the process with another real-life phenomenon, as well as the feasibility of creating more creative design ideas. In Phase 4, the characteristics or patterns in the actual concept generation process were inferred from those of the virtual concept generation process. The results suggest that thinking patterns in which expli...

A new method for evaluating the best product end-of-life strategy during the early design phase

Abstract: The choice of an appropriate end-of-life (EOL) destination for discarded products is becoming an important issue for most manufactured products, given the current problems of environmental waste im...

Change as little as possible: creativity in design by modification

Abstract: While design research has concentrated on creativity in the early phases of design and on creativity in very open-ended design tasks, in practice many design projects concern the modification or incremental development of existing systems to meet new needs and restrictions. Some projects adopt a process of defining, prioritising and propagating requirements and constraints that bypasses conceptual design as it is conventionally understood. However, incremental development requires creative design to deal with multiple conflicting requirements, both in early design and in solving later local problems: the challenge lies in finding a satisfactory solution while avoiding a cascade of changes to the rest of the system. This paper draws on two case studies, one of the design of a new generation of diesel engines and one of the refurbishment of a hospital ward, to argue that in these domains creativity is required to find designs that change as little as possible and meet the given requirements with minimal effort.

Reflections on diversity in design research

Abstract: Design is a topic that has been studied from many disciplinary perspectives, each bringing particular methodological traditions to bear and yielding many different insights into the subject, but the diversity has meant that it has been difficult to achieve a coherent and comprehensive view on research in the domain. This paper presents observations on this diversity in design research and then makes suggestions for action to identify opportunities for collaboration and consolidation. The design research ‘landscape’ is first characterised as involving a number of academic communities that research the topic from different perspectives. An approach is then presented to characterising research by considering facets such as the timescale of the design episode being studied, the phase of the design process and the complexity of the resulting artefact, and an example is given of its application to the papers presented at the International Conference on Engineering Design in 2009. Finally, suggestions are made f...

Supporting knowledge exploration and discovery in multi-dimensional data with interactive multiscale visualisation

Abstract: Knowledge discovery in multi-dimensional data is a challenging problem in engineering design. For example, in trade space exploration of large design data sets, designers need to select a subset of data of interest and examine data from different data dimensions and within data clusters at different granularities. This exploration is a process that demands both humans, who can heuristically decide what data to explore and how best to explore it, and computers, which can quickly extract features that may be of interest in the data. Thus, to support this process of knowledge discovery, we need tools that can go beyond traditional computer-oriented optimisation approaches and support advanced designer-centred trade space exploration and data interaction. This paper is an effort to address this need. In particular, we propose the interactive multiscale-nested clustering and aggregation framework to support trade space exploration of multi-dimensional data common to design optimisation. A system prototype of t...

Integrated product relationships management: a model to enable concurrent product design and assembly sequence planning

Abstract: The paper describes a novel approach to product relationships management in the context of concurrent engineering and product lifecycle management (PLM). Current industrial practices in product data management and manufacturing process management systems require better efficiency, flexibility, and sensitivity in managing product information at various levels of abstraction throughout its lifecycle. The aim of the proposed work is to manage vital yet complex and inherent product relationship information to enable concurrent product design and assembly sequence planning. Indeed, the definition of the product with its assembly sequence requires the management and the understanding of the numerous product relationships, ensuring consistency between the product and its components. This main objective stresses the relational design paradigm by focusing on product relationships along its lifecycle. This paper gives the detailed description of the background and models which highlight the need for a more efficient PLM approach. The proposed theoretical approach is then described in detail. A separate paper will focus on the implementation of the proposed approach in a PLM-based application, and an in-depth case study to evaluate the implementation of the novel approach will also be given.

FCBS model for functional knowledge representation in conceptual design

Abstract: This paper proposes the function–cell–behaviour–structure (FCBS) model for better comprehending representation and reuse of design knowledge in conceptual design. Two knowledge representing layers, i.e. the principle layer and the physical layer are proposed in the FCBS model. In the principle layer, we focus on the underlying design principles in previous designs and FKC (functional knowledge cell; a kind of function–cell pair) is utilised to represent the principle knowledge. A functional sketch is proposed for recording and demonstrating working principles of design alternative on a functional basis. In the physical layer, case modelling is employed to integrate the structural information and behavioural performances of the existing devices which applies the design principles represented by FKCs. A case is composed of structure and its behaviour. A case-based method is adopted to substantiate functional cells into physical structures in embodiment design, in terms of case embodiment. The behavioural pe...

A framework to support requirements analysis in engineering design

Abstract: Complex system development activities, such as requirements analysis (RA) to requirements specification, implementation and verification, are well defined in the software engineering domain. Interests in using a model-driven engineering have increased in this domain. System-level RA and model-driven engineering may result in a significant improvement in engineering design. This paper presents a Checklist-Oriented Requirement Analysis (CORA) framework to develop and formalize requirements. CORA is an integrated framework that adopts a checklist concept and utilises logical reasoning operation in conjunction with information management to analyse systematically the initial requirements statement. An underground work machine is used as an application example to illustrate the proposed framework.

A generalised collaborative optimisation method and its combination with kriging metamodels for engineering design

Abstract: In this paper, a generalised collaborative optimisation (GCO) method is proposed in the field of multidisciplinary design optimisation (MDO). In this method, the concept of generalised multidisciplinary variables is put forward and summarised as four types to provide more comprehensive interdisciplinary compatibility constraints than traditional collaborative optimisation. The linear normalisation method is adopted in GCO to remove inconsistencies caused by the range discrepancies between design variables. The effectiveness of GCO is demonstrated by its successful application in the design of a gear reducer. Furthermore, to undertake the computational and organisational challenges in MDO, an effective approach combining kriging and GCO (KGCO) is presented. In this approach, kriging metamodels are employed to reduce the computational cost by replacing expensive simulation and analysis codes. System-level compatibility constraints are approximated by kriging metamodels to remove the non-smoothness of the or...

A novel approach for complexity measure analysis in design projects

Abstract: This study report presents a graph-based model to measure the relative complexity of design projects. Using managerial and technical graphs and complexity design structure matrix, the relative complexity of design projects can be determined. The relative complexity measure can support assembly-oriented design, and guide the designer in creating a product with the most effective balance of manufacturing and assembly complexity. Furthermore, the complexity measures can be used as a yardstick for budgeting and resource allocation for future design projects or maintenance cost estimation. An illustrative example is demonstrated to present the application of the model.

A comparative study of changes across the lifecycle of complex products in a variant and a customised industry

Abstract: This paper focuses upon investigating the characteristics of engineering changes and identifying the main reasons for changes arising during the different phases of the lifecycle of complex engineering products. Two case studies representing products with different development processes have been selected and change documentation analysed. The two cases selected were: (1) a variant design product, an aeroengine and (2) a customised product, drilling equipment for the oil industry. The change requests were analysed to understand their distribution and motivation across the lifecycle of the two products. The findings show that change requests peak during the manufacturing phase and indicate that the motivation for change varies throughout a product's lifecycle. The results provide insights into the factors to be considered during the development process in order to reduce the number of change requests from the later phases of a product's lifecycle and to support designers to efficiently address the unavoida...

New dependency model and biological analogy for integrating product design for variety with market requirements

Abstract: Variety in product design is a result of diversity of needs in different domains and market segments. The two-way interaction and dependency between product design features and customer requirements is analogous to co-evolution in nature, where two groups of different species evolve to co-exist. A new method for designing products, families and platforms by recognising commonalities and core features, using the concept of co-evolution, is introduced in this paper. Cladistics is used to identify product component modules which correspond to common regional market requirements. Algorithms for functional and structural analysis as well as product variants generation have been developed. Complex dependency interactions and modularity relationships are modelled using liaison graphs and cladograms. A case study of washing machines is detailed and used to validate this novel application of the co-evolution dependency model in product families and platform design, demonstrating its use in the world of artefacts c...

Multiple-domain design scorecards: a method for architecture generation and evaluation through interface characterisation

Abstract: High-tech mechatronic system design, such as for tools for oil-well drilling and exploitation, requires that engineers from multiple domains concur on architectural solutions due to a large number of interdependent system performance criteria and design parameters that are shared across architecture interfaces. Supporting designers in envisioning probable challenges in architectures early in design is of utmost importance to ensure project quality while minimizing costs and delays. In this paper, we present the Multiple-Domain Design Scorecards (MDDS) method to facilitate architecture generation and assessment through architecture interface characterisation as well as to support design process management. We propose to semantically enrich the Design Structure Matrix (DSM), Domain Mapping Matrix (DMM) and Quality Function Deployment (QFD) representations to capture project data and expertise related to concept generation. In addition, we propose six types of Design Assessment Cards (DACs) that both support design space exploration and highlight design challenges of potential system architecture. The proposed approach is being implemented and tested in an industry context. A case study in the oil industry brings to the fore some of the advantages and challenges in the implementation process.

Optimal design processes under uncertainty and reciprocal dependency

Abstract: Design processes are characterised by uncertainty and iteration, making them difficult to plan and manage. These characteristics are incorporated into an original model in which information flow is simulated explicitly such that the dynamic complexity of design processes with interdependent tasks is captured. This is accomplished through the linkage of information exchange to the work done during each design task, the availability of resources, and the techniques used to manage the product development (PD) process. The model generates rework due to iteration and failure in design reviews according to the ability of tasks to reduce the uncertainty of design information. The model is applied to the investigation of coordination and its effects on process behaviour under various conditions. Coordination mechanisms are studied through the choice of input parameters that influence the degree of overlapping of tasks, the allocation of resources that process information, the delay of communication of information...

A survey-based methodology for prioritising the industrial implementation qualities of design tools

Abstract: The early use of design tools in new product development has a significant impact on competitive business performance. However, their implementation by companies is not always successful. The main aim of this paper is to enhance research methodology for the development of new design tools to aid successful industrial implementation. A survey of existing research associated with the development and implementation of a wide range of design tools is reviewed, and categorised in terms of their ideal attributes, why, how and when they should be implemented, who should be involved, and where they are best positioned in the product development process. Known issues considered as implementation barriers are also presented in terms of practitioner and manager perspectives. Priority implementation issues are further identified from requirements analysis and the implementation history of four specific design tools at different implementation statuses. These qualities are then discussed in the context of enhancing re...