Showing papers in "Guidelines for a Decision Support Method Adapted to NPD Processes in 2007"

A Classification of Uncertainty for Early Product and System Design

Abstract: Complex systems and products evolve over years to meet new requirements, while applying tried and tested technology. To maximise the reuse of components through the life span, companies need to plan for changes that they can anticipate and cannot anticipate, and facilitate accommodation of such changes in the original architecture and design of the system. However, the degree to which future product changes can be planned depends on the uncertainties that the system, product or product family is subject to. A deeper understanding of these uncertainties is the focus of this paper. The paper first provides a brief literature survey, and discusses the sources and nature of uncertainty. This is followed by a classification of the types of uncertainties that are often encountered and that should be considered, as well as methods and techniques for modelling these uncertainties for incorporation in system design. The paper also provides examples of uncertainties for a variety of systems and products throughout and concludes with an uncertainty checklist for system architects and product designers.

Design as Forcing: Deepening the Foundations of C-K Theory

Abstract: We present a new result about the consistency and validity of C-K design theory. C-K design theory [1] has been applied recently in a variety of industrial contexts. Paradoxically, C-K theory offers a constructive and rigorous method in non-programmable and creative situations. To solve the paradox of a theory that increases both design control and design creativity stronger foundations are needed. In this paper, we establish the correspondence between C-K theory and Forcing, a method of Set theory developed by Paul Cohen in 1963 for the “invention” of new sets. We show the deep relations between the two approaches. It appears that C-K operators generate potential and dynamic forcings in the real word. In return, Forcing warrants the creative process in C-K theory and explains why meaning can be preserved during an innovative design process. Taking into account the foundational aspects of Forcing in modern Set theory, these findings strengthen the validity of C-K theory and confirm that design theory can now claim a new scientific maturity.

Comparison of Three Methodological Approaches of Design Research

Abstract: This paper compares three framing methodologies of design research from: (a) ontological (what the framing methodologies actually are and why they exist), (b) epistemological (what the sources, structures, and contents of knowledge are), (c) methodological (what processes the framing methodologies imply, and what methods they involve), and (d) praxiological (to which problems the framing methodologies have been applied, and how they are working in the practice) aspects. The three framing methodologies are: (i) research in design context, (ii) design inclusive research, and (iii) practice-based design research. The first methodology supports analytical disciplinary research aiming at insights, understanding, and predictions, relies mainly on the knowledge of background disciplines, uses the research methods of these disciplines, lends itself to mono-disciplinary approaches, and concentrates on building and proving theories, which add to the disciplinary knowledge of design. The second methodology supports analytic disciplinary and constructive operative design research by the involvement of various manifestations of design in research processes as research means, integrates knowledge of multiple source domains, and lends itself to multi-disciplinary insights, explanations and predictions, but can also generate knowledge, know how, and tools for problem solving. The third methodology extracts knowledge from concrete practical design processes, environments, and artefacts, and it supports the improvement of design problem solving intelligence by exploring and constructing common principles, rules, and standards in a reflexive manner. In general, the three research methodological approaches are characterized by a growing level of contextualization, and by an increasing level of knowledge synthesis. They together offer a genuine methodological platform for doing design research.

Product/Service-System Development: An Explorative Case Study In A Manufacturing Company

Abstract: Product/service-systems’ (PSS) are innovation strategies where instead of focusing on the value of selling physical products, one focuses on the value of the utility of products and services throughout the product’s life period. This approach enables companies to provide customers with offerings that continuously deliver value and create a strong competitive advantage. PSS attempts to transcend the old industrial credo that value is embedded in products and the consideration of ‘cost-quality-time’ relates to the physical artefact. While there is increasing interest in PSS, limited research has been done in the design and development aspects of PSS. The objective of this paper is to explore how a global manufacturing company is developing an offering to their customers that is focused on the utility of their products throughout their life time. The paper describes the process of how a company is shifting from selling office furniture to selling the benefit of sustainable office workspace performance measured in economic, social and environmental terms. By relating the customer’s business performance to the activities associated with the use of office workspace the company may enhance the value of their products. This process of re-defining the value of what the company is actually offering to its customers is seen as a key element in PSS development. PSS development is expected to expand conventional product development in new directions, such as new activities, roles and responsibilities, knowledge and competencies, and value network relationships. The implications of this are discussed in relation to the company’s development approach.

Development of a Method for Assessing Design Creativity

Abstract: Creativity is regarded as a core ingredient of innovation as it enhances the possibility of generating superior products. The core components of creativity are ‘novelty’ and ‘usefulness’ and a direct measure of creativity should be in terms of measuring these components. This paper proposes a method for assessing creativity of technical products. Empirical studies have been conducted to validate this method. First this paper reviews existing methods for measuring ‘novelty’ of technical products, proposes a new method for measuring novelty, and evaluates the proposed method and the existing measures by benchmarking them against the intuitive notion of creativity of experienced designers. Next, it reviews existing literature on ‘usefulness’, proposes a method for assessing usefulness of technical products, and evaluates this by comparing its outcome with the outcome of the existing methods taking the evaluation by experienced designers as reference. Later, ‘creativity’ measures for these products are calculated using the values of the novelty and usefulness of the products and benchmarked against the outcomes of intuitive evaluation of creativity of these products by experienced designers.

Modelling Project Complexity

Abstract: As the underlying cause of many risks, complexity i s identified as a crucial issue within the field of project management. However, there is still a contr oversial debate about what complexity really is. Several factors seem to be drivers of project compl exity, but little is known about them. Complexity i s itself complex and many authors emphasize that atte ntion should be paid to define clearly the kind of complexity being managed. We believe that project p erformance is closely related to project complexity management. Consequently, once clearly d efined, project complexity should be accurately measured in order to drive more efficiently project complexity management. It should also be kept in mind throughout the reading of this paper that comp lexity can have both a negative influence on project performance and a positive influence on pro ject outcomes (since properties emerging from complexity can create new opportunities). As a cons equence, project complexity management should not consist in reducing or avoiding it but in mainting it in a good range. In this paper, we first focus on three different as pects of complexity: definitions of complexity and project complexity, existing models of project comp lexity, and existing measures of complexity and project complexity. We then argue that it can be mo delled through an interactions model between the different elements constituting the project system. We do believe that by defining those objects, thei r attributes and their interrelations through systemi cs, we are able to model project complexity. A firs t model was tested in partnership with PSA Peugeot Ci troën and proved to be helpful. This paper also aims at refining this model into a new model named ALOE and finally gives perspectives on how it will be further developed to enable its users to de fine a project complexity measure and link it more efficiently with project performance, so that they can finally lessen the number and impact of the ris ks and problems emerging from complexity.

Comparative Analysis of Uncertainty Propagation Methods for Robust Engineering Design

Abstract: One of the main stages of robust Engineering Design is the propagation of uncertainty in the computer analysis system. This paper presents a comparative study of various methods for uncertainty propagation, including some recently proposed derivative-free techniques called Sigma-point methods. The latter are assessed against more conventional techniques such as Monte Carlo simulation and moment propagation based on truncated Taylor series. The accuracy and computational efficiency of all methods is investigated by means of mathematical analyses and numerical examples. The solution of a robust optimization problem based on the presented methods is included. Theoretical analyses and numerical results highlight that the accuracy of robust optimization using Sigma-point methods can be enhanced with respect to that using moment propagation based on linearization without altering significantly the computational cost of a single optimization step. The paper also discusses the optimal deployment of Automatic Differentiation in conjunction with the uncertainty analysis technique chosen for the solution of the robust optimization problem and highlights the computational benefits that this yields to.

Change impact and risk analysis (CIRA) : combining the CPM/PDD theory and FMEA-methodology for an improved engineering change management

Abstract: The change process is one of the most critical tasks of the product development process. Misinterpretation or lack of knowledge about impacts or risks of changes can cause serious disadvantages to companies, e.g. high failure or change costs or image losses caused by products with a quality that is unacceptable. Supervising the change process is a challenging task; an important part of this task is the analysis and assessment of risks and impacts of changes. This contribution presents an approach to support the process of analysing and assessing the effects of changes in the product development process. The approach is based on two methods: First on the CPM/PDD theory developed at the Institute of Engineering Design/CAD in order to synthesise potential solutions to change requests and to ana-lyse their impacts; second on the common Failure Modes and Effects Analysis (FMEA)-method in order to assess the risks and impacts of changes and to document the analysis.

Engineering Change During a Product’S Lifecycle

Abstract: This paper describes a case study investigating the changes made to a complex product, namely an aero-engine through its product lifecycle. Document analysis of over 1500 reports covering eight years of the aero-engine lifecycle has been carried out. The research investigated how changes occur at different phases of a product lifecycle and how the causes of the changes differ during the different stages. The majority of changes were found to occur during the manufacturing and build phase. It was found that changes to the engineering specification together with meeting design criteria are the major causes during the prototype testing and development phase. The main cause of engineering change was found to be linked to its lifecycle phase.

A Vision to Overcome “Chaotic” Design for X Processes in Early Phases

Abstract: There is ample literature available dealing with specific questions regarding Design for X, where “X” takes various meanings such as assembly, manufacturing, cost, and recycling amongst many others. The multidimensional problem spread caused by the different “X” possibilities, generates tremendous complexity due to the large number of interdependencies. In practice, today’s product solutions are more or less based on the experience of a few designers and the results achieved are commonly suboptimal. Developers and researchers increasingly work more in dealing with interdependencies between domains a specific domain is a situation field that originates from the designer and the design process. Some domains that have a key impact to product development are often overlooked due to the complex nature of the varied development tasks. Following the influence matrix, the Design Structure Matrix (DSM) and the Domain Mapping Matrix (DMM) methods have evolved in this problem area. By combining the latter two methods and complementing them with strength-based graphs, a powerful and novel methodology has been achieved that is already available today. By adding the possibility of weighting interdependencies, it is now possible to take an important step towards crafting a method that supports designers during the entire product development process.

Towards Interoperability Between Functional Taxonomies Using An Ontology-Based Mapping

Abstract: A functional model of an artifact shows an important part of designer’s intention. A taxonomy of generic functions plays a crucial role in describing such functional models. Improving interoperability among functional models of different functional taxonomies facilitates sharing functional models among designers in organizations. The mapping between the different functional taxonomies and the conversion of functional models based on this mapping are one of the ways to support such interoperability. Among the different functional taxonomies, however, there are not only terminological differences but also ontological differences implicitly. By ontological differences we mean the conceptual differences between taxonomies and the general structural differences between models. In this article, firstly we propose a framework for mapping between functional taxonomies using a reference ontology of function in order to bridge the conceptual differences. The reference ontology contributes to specify the ontological differences between the functional taxonomies. Second, in order to reduce the structural differences between the functional models, we discuss how to capture the modeling world. These results enable us to convert the functional models among different taxonomies. As examples of the functional taxonomies, we focus on the reconciled functional basis proposed by Hirtz et al. and our functional concept ontology based on Function & Behavior Representation Language.

Creativity and Design Reasoning: How C-K Theory Can Enhance Creative Design

Abstract: Confronted today to increasing demand for innovation, engineers consider creativity as an indispensable albeit weird technique. How to combine the engineering design requirements for robustness and value achievement with the creativity capacity to get unheard original and varied ideas? How to control a “creative design process” with the rigor praised by engineering design? Based on recent theory of design reasoning, C-K theory, this paper shows that value, robustness, variety and originality can be efficiently combined in a theoretically grounded, well-mastered process. It shows how to avoid two main creative design traps, pseudo-creativity and bounded creativity; and how to manage two different types of creative design, value achievement vs value exploration creativity. These processes are illustrated on one specific case, the design of a “smart shopping cart”.

A Methodology of Engineering Ontology Development for Information Retrieval

Abstract: When engineering content is created and applied during the product lifecycle, it is often stored and forgotten. Since search remains text-based, engineers do not have the means to harness and reuse past designs, experiences, and mistakes. On the other hand, current information retrieval approaches based on statistical methods and keyword matching are not directly applicable to the engineering domain. The long term goal of this research is to develop an engineering ontology based computational framework in order to (1) structure unstructured engineering documents; and (2) achieve more effective information retrieval. This paper focuses on the method and process that acquire and evaluate the engineering ontology. We propose a principled, systematic, and semi-automatic ontology development methodology that is based on ontological semantics and is integrated with Protege, one of the most widely used ontology engineering tools. The methodology is applied in acquiring the established engineering knowledge from various resources. A preliminary test based on engineering catalogs, CAD drawings, and project reports has been conducted. The results validate the effectiveness of the engineering ontology as well as the methodology.

Evaluation Method for Selecting Innovative Product Concepts With Greater Potential Marketing Succes

Abstract: Product innovation helps companies to obtain competitive advantage and operate successfully in an increasingly global market. Product development (PD) is a lengthy, expensive process. Thus, companies have a crucial need to assess whether or not they are on the right track from the early stages of product development. That is, to know whether their product is going to be creative and a marketing success. A proper assessment will allow the right decisions to be made, leading to the development of innovative products. The conceptual design stage is critical when assessing the innovation potential of a product. In this stage, there is a shortage of methods to help companies identify the most innovative product concepts. In this article, a method for assessing the innovation potential of product concepts and selecting those with greater probability of success is described. To that avail, aspects regarding the degree of novelty of product concepts and their potential for success in the market are taken into account. These aspects were integrated into a modified QFD matrix. The proposed method was successfully applied in two companies.

Life Cycle Option Selection Based on the Difference of Value and Physical Lifetimes for Life Cycle Design

Abstract: Many products, such as cellular phone and personal computer, are thrown away because of obsoleteness of their functionality, although they still work well. This fact aggravates the waste problem and the shortage of resources. In order to avoid this problem, a designer should determine best mixture of life cycle options of a product and its components so as to utilize them until the very end of their lifetimes. One of the most critical factors is the mismatch between “value lifetime,” the time until a product is thrown away because of the above-mentioned reasons and “physical lifetime,” the time until a product breaks down. However, there are no methodologies to estimate the value lifetime, while physical lifetime can be estimated by using the reliability theory. This paper proposes a methodology for estimating both of physical and value lifetimes and selecting life cycle options of components based on the estimated lifetimes. The basic idea is to divide a product disposal distribution into a value disposal distribution and a physical disposal distribution of the product. This paper proposes “LCOP Selection Chart” for the latter issue. This paper also illustrates case studies of cellular phone, vacuum cleaner, new car, and secondhand car. The result of the case studies revealed obvious differences in disposal patterns of these products and successfully supported in selecting life cycle options. Therefore, the case studies verified feasibility and effectiveness of the proposed methodology.

Integrating New Product Development Process References With Maturity and Change Management Models

Abstract: One of the most recognized best practices to improve new product development (NPD) process performance is the use of business process models to integrate activities, techniques, and methods. In recent years new product development models have been proposed, with complementary contributions. The challenge is how to use them to identify the improvement opportunities and how to orchestrate change actions. This work presents a NPD model, named PDPNet, whose singular characteristic is the integration between a business process reference, a maturity model and change management model in order to support the full product development change cycle. This paper also presents the evaluation of this approach in a case study about the PDPNet model implementation at an agriculture machine company. The method of the field research is the case study. The collected data techniques were participant observation, documental analysis and research diaries. The main contribution is to demonstrate the advantages in using distinct models consistent with each other, specially the separation between the Business Process Reference Model, that is, the practices, methods and tools, from the Maturity Level Identification as proposed by the PDPNet Model.

A Model for Designing Product-Service Systems Using Functional Analysis and Agent Based Model

Abstract: According to people from management or engineering areas, developing a service is different from developing a product. Indeed, in the emergent service selling and in particular with the ProductService System paradigm, designers have to consider both physical products and immaterial services to satisfy the customers’ needs. So, the key issue for designers is to be able to develop jointly physical products, as it could be done with engineering product design process, but also taking into account services that interact with them. Consequently, engineering designers whom will develop PSS will have to be supported for developing both products and services involved in PSS. Moreover, they have to be assisted to validate the fact that they generate more added value with an integrate design of a PSS to be competitive. In order to develop in integrated way PSS elements, we propose a method based on functional analysis and agent-based value design by considering some value aspects. The Velo’v example will be used to illustrate our proposition.

Understanding Search in Design

Abstract: Search and exploration of idea spaces enhances creativity of designers a necessary ingredient of engineering design. Designers constantly explore and search design spaces to generate or identify solutions. Past research is surveyed in order to explore the current definitions, importance and understanding of the phenomena of search and exploration, and gaps in research in these areas are identified. Next, through design experiments, an in-depth understanding of the process of search and exploration has been sought. Creative efficacy of designers has been studied in relation to the kinds and amounts of search taken place during the design process, leading to the establishment of relationships of creativity with other factors such as experience, search characteristics and time. Finally, guidelines are proposed in order to help designers check their progress towards better designs by controlling the outcomes of the design process proactively during the early design phases.

A Function-Based Component Ontology for Systems Design

Abstract: A methodology for the systematic placement of components into a hierarchical ontology is proposed. Cues taken from the Linnaean classification system for living organisms were used to generate a hierarchical ontology for organizing component terms and to create a robust procedure for adding new component terms to an existing component naming scheme. The objective of this research is to begin constructing a hierarchical ontology that is analogous to the Linnaean classification system with specific rules that rigorously guide component placement within the framework. The primary motivation for this research is to develop an ontology of distinct components terms that supports computational strategies for automated design synthesis, general design knowledge storage and reuse, efficient communication of design information, and standardization for digital component cataloging and searching.

A Service Evaluation Method for Service/Product Engineering

Abstract: As a result of changes in the way consumers understand and determine value, the high value once placed on typical mass-produced products has diminished. Consequently, a new paradigm must be created to revitalize the global economy. New concepts have emerged which offer partial solutions: Service/Product Engineering (SPE) (formerly called Service Engineering), Product/Service Systems (PSS), Functional Products, and Functional Sales. In this report, a method for evaluating service solutions is proposed. Here, service evaluation is defined as an evaluation conducted by a provider during the design process in order to generate the largest value for all the concerned agents. First, a fundamental definition of service and elements for modeling a service are given. Quality Function Deployment (QFD), used widely in product design, and other mathematical methodologies are then employed. Finally, the proposed service evaluation method is used to evaluate a clothes-washing service in order to demonstrate the effectiveness of the method. In addition, a service evaluation tool based on the proposed method is described. The effectiveness of the proposed method is demonstrated, as is the usefulness of the tool as a structural element of a service CAD system for service design support.

A Hierarchical Requirements Modeling Scheme to Support Engineering Innovation

Abstract: The practice of requirements capture, modeling, and management is more advanced in some fields, such as software engineering, than is currently evidenced in the field of engineering design. This situation is due in part to the increased number of domains that engineering problems span. Software designers, for example, need not concern themselves with physical working principles, material selection, environmental regulations, safety tests, and so forth. To address this situation, we describe a matrix based hierarchical requirements modeling scheme capturing seven domains of interest to engineering design problems. We illustrate how the application of our modeling scheme can foster engineering innovation through examples drawn from automobile sub-systems.

Guidelines for a Decision Support Method Adapted to NPD Processes

Abstract: In the present paper a study of decision making processes in innovative Small and Medium Sized Companies from the Valencia region (Spain) is presented. The objectives of the study are: to determine what relevant groups of decisions are made in New Product Development, to determine how these decisions are made in this type of companies, to demonstrate that these companies do not as yet use Decision Support Methods and to obtain guidelines for a future development of a Decision Support Method adapted to these type of decisions and companies. To achieve these objectives, an empirical study covering a representative sample of innovative companies in this region was carried out. On one hand, the patterns of decision-making processes in these companies were obtained, extracting the main groups of decisions through a factorial analysis of the data. On the other hand, after a reliability analysis and a data correlations study, these results also show that two different company groups can be identified, according to the structure level of their decision-making processes. The existence of these two groups allowed us to identify different ways to support these companies in making these types of decisions.

Imparting Design Methods With the Strategies of Experts

Abstract: The development of design methods started with the experiences and individual findings of outstanding engineering designers such as Wogerbauer [1], Kesselring [2], and Pahl [3]. They describe their experience and findings in short texts and examples, addressing the individual thinking and acting of designers [2]. They are the first authors of design methods. One of their decisive aims was to further impart their experience and findings in order to ease and shorten the time necessary to become a fully-fledged designer. In their further development, design methods and their descriptions changed distinctively. They became more comprehensive and abstract, in order to gain scientific recognition and be suitable for a broad application in different branches. Analyzing this development and the different development stages of design methods makes evident that design methods embody different levels of knowledge concerning the levels of expertise and thus that of abstraction. Investigations of the authors of design methods [5] show that the development of design methods corresponds to aspects of gaining expertise. This paper addresses the question of what meaning these insights into design methods have in terms of their characteristics, application and impartation. The paper reveals certain characteristics of design methods and their authors concerning expertise, and concludes with important aspects for a more "design methods-suitable" education. The characteristics of experts, expert knowledge and expert learning-styles are key factors in these considerations.

Engineering change analysis during ongoing product development

Abstract: Engineering changes are part of any design process. Changes are often requested even before a product design has been completed. However, change requests during an ongoing design process are difficult to assess because the design is still evolving. Some parts, where only conceptual designs exist, may be easy to change; other parts may already be frozen and hence more difficult and probably more expensive to change. In order to find the best way to implement a change at a given time, the designer needs to be aware of not only the design and the interactions, but also of the state of development of every part. However, many designers are not always aware of all interactions and, hence, unexpected and expensive change alternatives are chosen. This paper focuses on the question of how designers can be made aware of the impact of a proposed change before they commit. It discusses the links between the product, process and people domains that interact during product development, listing limiting factors that make change implementation risky and lead to increased change cost. The paper presents a tool to evaluate change proposals during ongoing design processes where the state of the development of parts is taken into account. The tool extends the Cambridge Change Prediction Method which assesses the risk of changes propagating between two parts. The paper concludes with the findings of two tool evaluation studies.

A Representation of Carrier Flows for Functional Design

Abstract: This research investigates and establishes a convention for the functional representation of the primary/carrier flow relationship utilizing the Functional Basis for design. Through primary and carrier flows, a designer can focus a functional model to specifically represent an individual aspect of an electromechanical system. Inclusion of carrier flows in functional modeling also allows designers to capture the flow functionality of simply transporting another flow through a system. Adding a carrier flow convention will allow a product designer to properly represent the primary/carrier flow relationship within a product, and thus the designer will be better able to accurately store, access, and utilize functional models as a design tool. In this work, carrier flows are described and demonstrated in a specific electromechanical example to show how they can be applied to a functional model to illustrate a specific design focus. The same product is then shown with respect to the repository entry application to demonstrate how the design information can be stored for future access and utilization.

Introductory Procedure for Sustainability-Driven Design Optimization

Abstract: In response to the increasingly competitive global market, there is a growing interest in design optimization. Being able to include aspects of socio-ecological sustainability in product design should aid companies to both improve current competitiveness and to identify viable long-term investment paths and new business opportunities in the evolving sustainability-driven market. A case study of a water jet cutting machine is used to illustrate a new iterative optimization procedure that combines a technical assessment with a sustainability assessment. Sustainability assessment methods/tools are first used to identify prominent sustainability problems from present-day flows and practices (“societal indicators”) and to generate ideas of long-term solutions and visions. Based on this, preliminary ideas about likely desirable changes in machine properties are obtained. Technical investigations are then performed to assess if/how these particularly desirable changes in machine properties could in principle be realized through changes in design variables. After that, obtainable changes are fed back to a new and more refined sustainability assessment to find out the societal implications of these changes. This may in turn result in other desirable design changes, which may call for a new and more refined technical assessment, etcetera. The experience from the case study indicates that the suggested integrated and iterative working procedure should be able to add information about socio-ecological impacts of product properties and influence design criteria used in prioritisation situations during product development.

Integrating Function-Based and Biomimetic Design for Automatic Concept Generation

Abstract: This paper explores combining functional modeling and biomimetic design. Observed benefits of applying functional modeling to biomimetic design include a more complete, systematic modeling that reveals additional aspects of biological phenomena to be exploited. Incorporating biological phenomena into a function-based design repository requires that multiple facets of the potential solution be presented, including a natural-language description of the biological phenomenon, the strategy derived from the phenomenon, example implementation of the strategy in engineered solutions, and functional modeling of both biological and engineered systems. This paper will illustrate the functional modeling of a single biological phenomenon at multiple levels of biological organization (organism/organ and cellular/molecular), the use of multiple biological analogies present in a single phenomenon in different engineering problems, and how the combination of functional modeling and biomimetic design leads to more complete exploitation of biological phenomena, as well as more complete representation of stimulus when including biological phenomena in a design repository.

Product Models in Design: a Combined Use of Two Models to Assess Change Risks

Abstract: When designing complex products such as robots or jet engines, companies face the problem that designers lack the necessary tools to predict the behaviour of the product in the case of component change, and to assess the risks associated with decisions. Product models allow companies and individual designers to reason about product properties. The information in the model can be used to analyse the properties of a product before decisions are taken about potential modifications. To meet time and budget constraints it is vital to have the ability to predict the risks of knock-on effects before a change is implemented and select alternative changes accordingly. This paper introduces a comparison of two product models used in the Change Prediction Method (CPM) and the Contact & Channel Model (C&CM). It analyses ways where both approaches can benefit and complement each other in analysing and predicting product change.

An Ontological Model of Emergent Design in Software Engineering

Abstract: This paper proposes an ontological account of a recent model of software engineering: emergent design. This model augments traditional software design approaches by accounting for incremental and unexpected modifications of the design state space. We show that the principles of emergent design are consistent with a model of designing as a reflective conversation. We use the situated function-behaviour-structure (FBS) framework to represent the activities driving emergent design. This is a basis for increasing understanding and acceptance of emergent design.

Ffip: a Framework for Early Assessment of Functional Failures in Complex Systems

Abstract: Ensuring the reliability of complex software intensive systems is becoming a critical requirement for all military and commercial aerospace applications, and becomes especially more challenging when implemented for autonomous and evolving deployments required of such applications. To ensure reliability, this research asserts that knowledge, data, and models of such complex systems must be integrated with their intended systems starting from the early design stages, hence enabling designers and engineers to plan for contingencies, redundancies, and potential changes early, before costly design decisions have been made. In this paper, a general system-level design methodology is introduced to perform simulation-based failure identification and propagation analysis of softwarehardware systems. In particular, the Functional Failure Identification and Propagation (FFIP) analysis framework is introduced as a novel approach for designing reliable software-intensive systems. A combination of function, structure, and behaviour modelling is proposed to simulate failure propagation paths and the resulting functional failures to determine mitigation options, integrating hierarchical system models with behavioural simulation and qualitative reasoning. The overall goal of this research is to develop a formal framework and simulation-based design tool for design and system engineering teams to evaluate and assess the potential of functional failures of software intensive systems throughout the lifecycle.