Interfaces Per Module: Is There an Ideal Number?

Identifying an appropriate level of abstraction for a technical system is a task often left to more experienced product designers. Based on a systematic approach to modular product design, experience has shown that module interfaces are a key factor in identifying this appropriate level. The foundation for this research is that there are an ideal number of interfaces that corresponds to three semiotic, or signed, notational levels of product design communication. This report will present an empirical metric that represents this ideal number, which can be used to assess the quality of the decomposition based on the number of interface types. The conclusion of the report is that the empirical value very closely matches the semiotic theory of three interfaces per module.