Procedure Model for the Indication of Change Propagation

Paper in proceeding, 2014

Engineering changes (EC) occur within the product development and account for up to 50% of its capacities [Lindemann 1998]. Despite the fact that ECs are necessary to improve a product’s quality and that they often are the source for innovation [Fricke 2000], ECs are also costly and bear the risk of propagating further through the product. Propagation occur when a change to one part of the system will trigger subsequent changes in other parts [Yang 2011]. In recent years, many methods on change propagation have been developed which aim at supporting designers assessing alternative change options. These methods, however, often apply to different scopes and intend at answering different questions, which makes it difficult to know which one to choose for one’s own specific situation. For instance, some methods aim at indicating potential change propagation paths so that product designers can see what other components are to be affected in the course of the initiated change, others, on the contrary, aim at calculating the risk for a change to propagate. Some methods are delimited to certain stages during product development such as the conceptual design phase, whereas others can be applied throughout all product development stages. Some methods map physical components, whereas others are able to map functional or parameter linkages in a product, etc. Hence, the methods developed in recent years differ to each other with regards to various aspects such as purpose or expected outcome. This means that, depending on the situation and intention of the product developer, not all methods are equally suitable. Thus, product developers who find themselves in a situation where alternative ways of implementing a change in order to meet the new requirement or to correct faults are available might question themselves what methods are out there that can support them and which of them is the most suitable. Therefore, this work’s objective is to develop a procedure model for product developers that can be used as a guide to decide what method for EC propagation fits best to their specific application environment and shall therefore be chosen. This paper’s definition of ECs is based on the definitions from Jarratt et al. [Jarratt 2011] and Conrat [Conrat 1998]: ECs are modifications in forms, fits, materials, dimensions, functions, drawings or software of a product or component that has already been released during the production design process. ECs include the connected process changes and can be of any size or type, can involve any people, and can take any length of time. This paper’s definition of EC propagation is based on Tang et al.’s [Tang 2008] and Koh et al.’s [Koh 2012] definition: EC propagation originates from the relationships or dependencies between items, such as between components, parameters, functions, etc., and describes the process by which a change to one part or element of an existing system configuration or design results in one or more additional changes to the system, when those changes would not have otherwise been required.