Product architecture and the propagation of engineering change

Research in Engineering Design, 2011

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 of the product as a whole or in part, and may alter the interactions and dependencies of the constituent elements of the product. Key aspects of the engineering change process are highlighted along with the tools and methods that are available to support the process. The nature of products (in terms of complexity, architecture and degree of innovation) and how that affects engineering change are covered. Important related areas such as organisational structure and employee attitudes are also highlighted. The paper concludes by discussing different strategies that have been proposed to cope with engineering change in today’s manufacturing environment.

Research in Engineering Design, 2004

Based on a detailed case study on change and customisation to existing products in the aerospace industry, this paper presents a comprehensive analysis of the problems and processes associated with product change. It looks at the potential causes and effects of changes, and analyses the formal and informal processes that are used to handle change. Change processes become problematic when change to one system propagates to other systems, because the tolerance margins of individual parameters are exceeded. The paper concludes with suggestions for handling change.

2007

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.

Journal of Mechanical Design, 2011

Engineering changes are an inherent part of the design and development process and can play an important role in driving the overall success of the system. This work seeks to create a multidimensional understanding of change activity in large systems that can help in improving future design and development efforts. This is achieved by a posteriori analysis of design changes. It is proposed that by constructing a temporal, spatial, and financial view of change activity within and across these dimensions, it becomes possible to gain useful insights regarding the system of study. Engineering change data from the design and development of a multiyear, multibillion dollar development project of an offshore oil and gas production system is used as a case study in this work. It is shown that the results from such an analysis can be used for identifying better design and management strategies (in similar systems and projects) and for targeting design improvement in identified subsystems. Th...

The main challenge for product designers, especially of complex products, is to predict as finely as possible the consequence of the product change for its structure as well as its propagation overall the Technical Information System (TIS). Starting from the work already undertaken in this domain, we underline the lack of methods and tools of impact analysis. Our contribution is therefore to bring a method with the aim to facilitate the impact analysis in a multi TIS context. This method, based on a product model supported by a constraints resolution tool, will allow resolving the various constraints levered in an impact analysis problem.

Changes and modifications in forms, fits, materials, dimensions, functions, etc. of a product or part are referred to as product design changes before the design is released, or engineering changes (ECs) after the design is released. An EC usually includes a resulting series of downstream changes along the product development process. Organisational, technological and operational changes are often causes for ECs [1]. ECs are a very significant issue in any product development process and especially in any new product development process. The scope of this paper is to report on the use of a specific business process modelling and simulation technique, namely System Dynamics, in order to develop an efficient and effective Engineering Change Management System. System Dynamics is a modelling technique that is especially suited for modelling, simulating and analysing the behavioural aspects of a system, i.e. the way that the system elements interact and influence each other to generate overall system behaviour. In terms of the New Product/Service Introduction (NP/SI) process, such an analysis can reveal positive or negative feedback loops in the process, thereby allowing managers to understand the likely impact of ‘local’ changes on overall process cost, time, and perceived quality. To the best of our knowledge this is the first attempt to use the methodology of System Dynamics in order to develop an Engineering Changes Management System. The primary aim is to simulate the NP/SI process of two particular companies in Greece and get an indication of the relationship between cost, time and quality. Furthermore, by inserting disturbances into the models and then simulating the NP/SI processes, it is possible to get an overview of the effects of ECs throughout this process. The results of the simulation process together with the ECs background, can provide the basis for developing an Engineering Change Management System, which when managed effectively can lead to an improved environment for product innovation, and provides a favourable opportunity for increased sales and profits.

2008

Systems Research and Behavioral Science, 2018

Many organizational problems are addressed through change to existing Information Systems (IT) rather than radical new design. In the face of high incidence of IT project failure, devising effective ways to tackle this type of change remains an open challenge. The paper discusses the motivation, theoretical foundation, characteristics and evaluation of a novel framework, referred to as POE‐Δ, which is rooted in design and engineering and is aimed at providing systematic support for representing, structuring and exploring change problems. We generalize an existing theory of greenfield design as problem solving for application to change problems: from a theoretical perspective POE‐Δ is a subset of its parent framework, allowing the seamless integration of greenfield and brownfield design to tackle change problems. Its initial case study evaluation shows that POE‐Δ allows the systematic analysis of change problems, leading to clearer understanding and better informed decision making. ©...

Design 2008: Proceedings of the 10th International Design Conference , 2008

Engineering changes occur in every life cycle phase of a product and in every step of the product development process. Today, the importance of engineering change management as a part of product development is constantly rising. Reasons besides the globalisation are that customers are interested in more customised products at the price of a mass product - a phenomenon [Eckert et al. 2003] call mass customisation -, failures in design and changes in customer wishes that can not entirely be prevented. According to Lindemann and Reichwald [Lindemann et. al. 1998] engineering change management consumes 30 to 50 %, sometimes even up to 70 % of the capacity in product development. According to Wildemann [Wildemann 2006] the average cost of one engineering change is about 1.400 EUR (working hours, scrapping and tooling cost, but no organisational cost). Multiplied with 425 changes per month in average, identified by Deubzer et. al. [Deubzer 2005], that results in 7.1 million EUR change cost per year for an average company in the automobile manufacturing industry. According to the rule of ten [VDI2247], engineering changes become more expensive and time consuming the later they occur in the product life. Hence, it is advantageous to perform changes as early as possible [Lindemann et al. 1998]. But on the other hand, today’s markets and customer wishes change so quickly that a frontloading of engineering changes hinders the technological development of a company and endangers competitive advantages through innovation and customisation. Additionally, again according to Lindemann and Reichwald [Lindemann et. al. 1998], about 40 % of changes are recognised only after the completion of the production tools. That is supported by Wildemann [Wildemann 2006] who states that 50 % of the design-related changes happen in the pre-series and series phase of the product development process. Approaches like Design for Changeability help to reduce change cost but even can not foresee all possible changes. Therefore, (engineering) change management is still an important task in product development. Thereof, especially the area of change impact analysis is the most significant part.

2011