Sangjin Jung

New modularity indices for modularity assessment and clustering of product architecture

ABSTRACT Modularity indices based on Design Structure Matrices (DSMs) have been utilised to help measure modularity and cluster a product’s architecture into independent or coordinated modules, but many metrics have difficulty (a) measuring the modularity of different types of architectures in real-world products such as bus-type architectures and (b) optimising module boundaries in architectures. After reviewing existing modularity indices and clustering algorithms, we introduce new modularity indices that can capture the degrees of (1) connection strengths within each independent module and between different modules, (2) density of connections within each module and between modules, (3) proximity of interactions to the diagonal of the DSM, and (4) density of connections between buses and other components. Moreover, the proposed metrics can serve as objective functions to obtain optimal DSMs to maximise modularity. A comparative analysis of the proposed modularity index shows that the proposed metric can measure the modularity for 28 different types of DSMs unlike other metrics. Also, the module definition results for an aircraft engine with complex connections between components indicate that clustering using the new modularity indices can help obtain optimal modular product architectures with higher modularity compared to existing clustering results in the literature.

Using Interfaces to Drive Module Definition: Investigating the Impact of a New Design Dependency Measure

Structural representations for interfaces between modules and components in a product vary widely in the literature. After reviewing several structural approaches to interface definition, a new weighted design dependency measure is described. The new representation takes into account both six different types of interfaces as well as their relative strength and frequency within a product architecture. The resulting design dependency measure provides a means for designers to quantify the change resistance in a product. In this paper, we investigate the use of this new design dependency measure to drive module identification. Specifically, we compare the resulting modules obtained by optimizing Design Structure Matrices (DSMs) using standard 0-1 representations of the interfaces to those obtained using the new design dependency measure. The results indicate that the weighted design dependency measure leads to more a logical definition of modules that maximizes within module dependencies and minimizes interactions between modules.Copyright

An Integrated Approach to Product Family Redesign Using Commonality and Variety Metrics

Redesigning a product family entails carefully balancing the tradeoffs between commonality and differentiation that are governed by the underlying platform architecture. Numerous metrics for commonality and variety exist to support product family design; however, rarely are they used in concert to redesign platforms effectively. In this paper, we introduce an integrated approach using multiple product family metrics to establish an effective platform redesign strategy. Specifically, we present a detailed procedure to integrate the Generational Variety Index (GVI), Product Line Commonality Index (PCI), and Design Structure Matrix (DSM) to prioritize components for redesign based on variety and commonality needs. The integrated approach extends to the platform architecture and establishes a redesign strategy for interfaces between components in the platform architecture. To demonstrate the approach, case studies involving two generations of wireless computer mice and two families of dishwashers are presented. Ongoing and future work are also discussed.Copyright