A matrix representation of the CPM/PDD approach as a means for change impact analysis

Abstract

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 preseries 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.