This document uses a meta-modelling approach to identify commonalities among ten smart manufacturing reference models. Each reference model is placed into the context of the meta-model to facilitate analysis of both common and distinct features. Major smart manufacturing reference model topics are identified, and the reference models compared within each topic.

As part of the meta-modelling approach development, a collection of models differing in extent of abstraction characterizes the evolution of a particular smart manufacturing system from the meta-model through a unifying smart manufacturing reference model and successively less abstract domain models to a model for system implementation.

This document presents a range of issues and challenges for further work to specify a high-level smart manufacturing reference model that unifies the concepts and practices identified using the meta-model approach analysis of the smart manufacturing reference models.