Genre: Information/Explanation

Different types of change processes . Type III curve highlights the effects change propagation on project schedules Performing engineering changes is an essential part of design . Yet seemingly harmless alterations to components may have undesired effects in a product , necessitating the need for changes to other parts of the product . The implications of change propagation can be very severe as they may lead to delays in schedules as well as placing excessive strain on resources . Motivation Literature on engineering change management shows that design engineers need support with assessing the impact of proposed changes . Findings from previous case studies on engineering change processes also suggests that there are potential benefits in using hierarchically decomposable product models to assess the impact of change . Objectives To develop an in-depth understanding of change propagation phenomena To highlight factors which contribute to change propagation in products To investigate suitability of hierarchical product models to support engineering change impact analysis To develop methods for assessing the impact of engineering changes To assess the use of such methods in predicting changes in industry Method An extensive literature review was carried out in conjunction with an in-depth analysis of data collected during case studies on engineering change processes in three UK companies . Based on the understanding gained , simple product models are used to analyse hypothetical change scenarios . Findings The literature review showed that strong coupling between component pairs often forces changes to propagate between them . Also , components may have strong dependencies between them even though they may not interact directly . These couplings are not always obvious due to the complex nature of component interactions . Early results suggests that hierarchical products models may be suitable for modelling such complex interactions to enable effective product change impact analysis . Acknowledgements Support for this project was provided by EPSRC . Key References ARIYO , O.O. , ' A multilevel product model to support engineering change management ' , CUED , PhD interim report . ARIYO , O.O. , ECKERT , C.M. and CLARKSON , P.J. ( 2004 ) ' Tolerance margins as constraining factors of changes in complex products ' in 5th Integrated Product Development Workshop , IPD 2004 , Magdeburg , Germany , ( CD-ROM ) .