This paper explores how change propagation analysis can be affected by the way system boundaries are defined. This is an important issue as engineering change can in reality propagate out of the system modelled and back through components that were not considered. The work builds on a diesel engine case study to examine the difference in analysis results generated based on a full system model (i.e. entire engine) and those generated based on a set of partial system models (e.g. sub-assemblies). It was found that partial system models with boundaries defined by physical sub-assemblies can produce analysis results that are highly correlated with the one produced using a full system model. It was also revealed that modelling more components (i.e. a more complete system model) does not necessarily increase the level of correlation. The findings can be used to support system boundary decisions in change propagation analysis.@en

A simulation model to help manage change propagation through design workflows is introduced. The model predicts resource requirements and schedule risk of a change process, accounting for concurrency, multiple sources of change, and iterations during redesign. Visualizations provide insight to answer common management questions. The approach is illustrated using an aircraft design workflow from Airbus and a more complex turbine disk design workflow from Rolls-Royce.@en

The delivery of products and services or capabilities over long product life-cycles requires extended support of engineering and management tasks by knowledge and information management. Integrated models, which capture information about product, process and rationale, have been developed and proposed in the literature to support the different product life-cycle phases as well as the reuse of components, modification and update of products. Information needs, which have been identified in previous engineering studies, are contrasted with the elements from integrated models. A systematic literature search identified models that are briefly described and their elements are contrasted with a schema of information needs derived from engineering research. The analysis identifies a lack of consensus (at basic syntactic and semantic levels) among the models and significant disparities in their coverage of the needs. Detailed examination of the models also reveals varied granularity in terms of number of model elements utilised to describe specific needs. Based on the findings, information categories are classified into a core set for future integrated models and additional candidate and related information needs. The benefits beyond modelling are also discussed.@en

Engineering changes are essential for any product development, and their management has become a crucial discipline. Research in engineering change management has brought about some methods and tools to support dealing with changes. This work extends the change prediction method through incorporation of a function–behaviour–structure (FBS) scheme. These additional levels of detail provide the rationales for change propagation and allow a more proactive management of changes. First, we develop the ontology of this method based on a comprehensive comparison of three seminal functional reasoning schemes. Then, we demonstrate the FBS Linkage technique by applying it to a diesel engine. Finally, we evaluate the method.

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An approach to cope with changing market needs is to design engineering systems that can be changed easily. However, in order to identify suitable candidates to be made more changeable, one has to be able to analyse the changeability of engineering systems. Hence, this paper introduces a dependency modelling technique that seeks to support companies in assessing the changeability of complex engineering systems. The research was carried out based on the design research methodology with a focus on method development. The primary result of this work is the provision of a design support that can be used to provide an estimation of system changeability by examining (1) the initiating points of change, (2) the direct propagation of change, (3) the indirect propagation of change, (4) the likelihood of change, and (5) the impact or effort of change. The technique developed uses a matrix-based approach and draws on the change prediction method to generate change indices for individual system components. By referring to the change indices generated, the changeability of engineering systems can be examined systematically. A heavy-duty diesel engine is used in this work as an example to demonstrate how the technique can be applied.

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Engineering changes are inevitable and might propagate within and across multiple boundaries. Their management has increasingly become relevant within the interdisciplinary field of systems engineering. A few literature categorization frameworks arising from literature reviews have been proposed to structure the research field of engineering change management. However, the literature reviews are limited in scope, and the existing categorization frameworks do not provide sufficient coverage of the research field in its broader context. This paper addresses both shortcomings. First, a new, holistic and process-oriented literature categorization framework is proposed. Second, this proposed framework is used to categorize a comprehensive list of 427 publications in engineering change management. This categorization highlights not only research areas which have gained much attention, but also those where little research has been done. Third, a citation analysis is conducted which reveals the links between the publications and indicates the most cited publications. The result of this paper will help researchers and managers to (1) navigate through the state of the art in engineering change management, (2) position their work in the overall picture of engineering change management, (3) focus on the identified research gaps and weak points, and (4) search for further research and improvement opportunities.@en

Engineering changes (ECs) are raised throughout the lifecycle of engineering products. A single change to one component produces knock-on effects on others necessitating additional changes. This change propagation significantly affects the development time and cost and determines the product's success. Predicting and managing such ECs is, thus, essential to companies. Some prediction tools model change propagation by algorithms, whereof a subgroup is numerical. Current numerical change propagation algorithms either do not account for the exclusion of cyclic propagation paths or are based on exhaustive searching methods. This paper presents a new matrix-calculation-based algorithm which can be applied directly to a numerical product model to analyze change propagation and support change prediction. The algorithm applies matrix multiplications on mutations of a given design structure matrix accounting for the exclusion of self-dependences and cyclic propagation paths and delivers the same results as the exhaustive search-based Trail Counting algorithm. Despite its factorial time complexity, the algorithm proves advantageous because of its straightforward matrix-based calculations which avoid exhaustive searching. Thereby, the algorithm can be implemented in established numerical programs such as Microsoft Excel which promise a wider application of the tools within and across companies along with better familiarity, usability, practicality, security, and robustness.@en

Engineering changes (ECs) are essential in complex product development, and their management is a crucial discipline for engineering industries. Numerous methods have been developed to support EC management (ECM), of which the change prediction method (CPM) is one of the most established. This article contributes a requirements-based benchmarking approach to assess and improve existing methods. The CPM is selected to be improved. First, based on a comprehensive literature survey and insights from industrial case studies, a set of 25 requirements for change management methods are developed. Second, these requirements are used as benchmarking criteria to assess the CPM in comparison to seven other promising methods. Third, the best-in-class solutions for each requirement are investigated to draw improvement suggestions for the CPM. Finally, an enhanced ECM method which implements these improvements is presented.

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This paper presents a modelling method that seeks to support the prediction and management of undesired engineering change (EC) propagation during the design and development of complex products. The method builds on the house of quality and the change prediction method to model the effects of potential change propagation brought about by different change options. The objective is to better reflect how well each change option can address the product requirements. The method was applied to the design of a jet engine fan during a case study with an aerospace company. The findings suggest that this modelling approach is suitable for assessing the effects of potential EC propagation and can support companies in effective exploration of the design space.

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Engineering change (EC) is a source of uncertainty. While the number of changes to a design can be optimized, their existence cannot be eliminated. Each change is accompanied by intended and unintended impacts both of which might propagate and cause further knock-on changes. Such change propagation causes uncertainty in design time, cost, and quality and thus needs to be predicted and controlled. Current engineering change propagation models map the product connectivity into a single-domain network and model change propagation as spread within this network. Those models miss out most dependencies from other domains and suffer from hidden dependencies. This paper proposes the function-behavior-structure (FBS) linkage model, a multidomain model which combines concepts of both the function-behavior-structure model from Gero and colleagues with the change prediction method (CPM) from Clarkson and colleagues. The FBS linkage model is represented in a network and a corresponding multidomain matrix of structural, behavioral, and functional elements and their links. Change propagation is described as spread in that network using principles of graph theory. The model is applied to a diesel engine. The results show that the FBS linkage model is promising and improves current methods in several ways: The model (1) accounts explicitly for all possible dependencies between product elements, (2) allows capturing and modeling of all relevant change requests, (3) improves the understanding of why and how changes propagate, (4) is scalable to different levels of decomposition, and (5) is flexible to present the results on different levels of abstraction. All these features of the FBS linkage model can help control and counteract change propagation and reduce uncertainty and risk in design.

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Engineering change has grown steadily in prominence both as an important issue for industry and as an active academic research area. This paper provides a categorised overview and perspective on the published academic literature on engineering change. The aim is to give new researchers an understanding of the field's breadth and depth, as well as pointers towards additional information, and established researchers a non-dogmatic summary perspective on the work accomplished in this area. Change is defined as an alteration made to parts, drawings or software that have already been released during the product design process and life cycle, regardless of the scale or the type of the change. A change may encompass any modification to the form, fit and/or function.

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Hospitals are facing a triple challenge - meeting mandatory climate change targets and refurbishing aging infrastructure while simultaneously providing quality of care. With the potential of more frequent disruptive weather events, a UK government-funded project was launched in 2009 to investigate practical strategies for the National Health Service to increase its resilience to climate change. This paper presents the process of defining resilience by using the Delphi method and demonstrates its applicability within healthcare design. A Delphi survey is nearing completion which has determined the significant resilience issues and temperature ranges for ideal and critical conditions. Our preliminary findings identified six priorities that lead towards increasing resilience. Using the Delphi method can be a useful tool in clarifying the focus for healthcare design considerations.@en

Within organisations, decision makers have to rely on collaboration with other actors from different disciplines working within highly dynamic and distributed associated networks of varying size and scales. This paper develops control and influence networks within Design Structure Matrices (DSM); applying the Change Prediction Method (CPM) tool. It posits the idea of the 'Networks-in-Being' with varying individual and collective characteristics. [Social] networks are considered to facilitate information exchange between actors. At the same time, networks failing to provide trustedinformation can hinder effective communication and collaboration. Different combinations of trust may therefore improve or impair the likelihood of information flow, transfer and subsequent action (cause and effect). This paper investigates how analysing different types of network-structures-inbeing can support collaboration and decision-making by using the change prediction method as a way of scoping information propagation between actors within a network.

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This paper presents the results from a UK survey about the knowledge and information requirements of managers and engineers in design and service. The survey aimed to gather requirements regarding the needs for retrieval of previous designs and the needs to capture knowledge and information from current designs to support future engineering tasks. The survey nature, method and instruments are described with the information and knowledge categories identified. The findings are analysed and contrasted with the results of other empirical studies. Notable results include the variety of information needs, unexpected absences and low frequency categories, the expectation of practitioners that tomorrow's needs will be similar to today's, the apparent failure to satisfy those needs, and suggestions from respondents for improvements.

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As a result of easier and faster iterations during the design process, the management of design changes, their propagation and their impacts are likely to become increasingly important in future. This paper uses a simulation model to investigate whether, and to what degree, a better understanding of how change propagates could help mitigate some of the risks to project performance that will arise from the increased dynamic complexity in future design environments. We conclude that accurate prediction of change propagation only a few steps ahead could significantly reduce unnecessary rework.

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It is common to develop new products through engineering changes (Jarratt et al., 2005). However, such changes can propagate undesirably (Eckert et al., 2004) especially for complex technical systems (e.g. Giffin et al., 2007). It is thus important to model and predict how engineering changes can propagate in order to better manage the design process of complex products. To address this, various authors have developed matrix-based approaches to model the dependencies between different engineering domains. For instance, Mocko et al. (2007) describe the use of a matrix-based modelling scheme which analyses the inter-relationships between engineering domains such as system requirements, functions, components, engineering characteristics, and test. In this paper, we extend the analysis by presenting a method which explicitly considers the effect of engineering change propagation. The goal of the method is to direct engineers to critical change propagation paths early and support engineers in the assessment of solution alternatives during preliminary design. Such assessment is analogous to the concept selection phase as described by Ulrich and Eppinger (1995) except the evaluation criteria are broader and considers both the product and the organisation.@en

This paper describes a software tool that demonstrates the effects of common vision and hearing impairments on image and sound files. This helps designers to understand and empathise with the difficulties that less able users might experience when using their products and interfaces. A range of impairments and severity levels are simulated and guidance is provided on how to address some of the issues raised. The latest version of this tool will be available for demonstration at Assets.

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