A probabilistic design reuse index for engineering designs

Many companies offer a range of related products that are constructed using similar components and processes. This enables them to meet customer expectations of product variety while minimizing the overheads (e.g., development and manufacturing costs). To support the management of product variety several indices have been proposed in the literature that measure the degree to which component use is standardized across products within the same product family. However, the derivation of some of these statistics can be laborious to calculate due to the effort required to assemble the necessary information. In this paper, we develop an index more suited to the automated data-mining of a company’s product portfolio, which is derived from the Kullback–Leibler divergence. The new measure provides an easily computed probabilistic measure that can be used to characterize the degree of component reuse within a single product, across a family of products, and at the individual component family level. To illustrate their applications, the indices and several existing measures are calculated for two contrasting product types; using the non-differentiating components of two flat-pack furniture ranges and the components of a range of bicycles.