Product modularity: measures and design methods

This paper presents an overview of existing research on measures of product modularity and methods to achieve modularity in product design. Discussions of the development of modular products have increased in recent years. The research activity into the development of modularity measures and methods has also increased. These measures and methods vary considerably in purpose and process. Some are highly quantitative and some are completely qualitative. Some are information intensive and some are more easily applied. The relationship to product platform planning is also shown. This overview shows no clear consensus beyond those found in the definition of modularity. There are, however, several themes that are prevalent. Most measures center on measuring dependencies with components external to modules. Some measures include a measure of component similarity. However, what is measured as dependencies and similarities varies by measure and by context. Additionally, there is always some subjectivity in the measures. The design methods vary greatly. Many are based on measures. Most are information intensive. Noticeably, the measures and methods lack rigorous verification and validation. There is also a lack of quantitative comparison among the various measures and methods. It is hoped that this research will highlight the present inconsistencies in the field of modular product design and put forward some critical questions, which will shape future research into this field.