The recently launched SPARK project (www.spark-project.net), aims to understand how Spatial Augmented Reality (SAR) technology can be used to support the co-design process. The project aims to develop, build and test a SAR technology for co-design. This paper presents the testing of a suite of metrics to assess the performance of co-design sessions in industry. These metrics will be needed in the SPARK project to help iteratively develop that technology, as well as to provide insights into the overall effects of using SAR tools in co-design. The aim of the study reported in this paper was to design, develop and test a process for applying a suite of co-design session metrics. During the study, the metrics application process was applied to two industry cases and based on the outcomes, refinements were made. This resulted in a proposed process for the evaluation of the effectiveness of co-design sessions. The work presented in this paper will be of particular interest to other researchers seeking to evaluate the impact of a product development tool on a specific design session.