Collaborative engineering is the practical application of collaboration sciences to the engineering domain. In today's highly connected technology-driven economy, the production industry must rely on the best practices of collaborative engineering to stay competitive when designing, manufacturing and operating complex machines, processes, and systems on a global scale. Despite its importance, collaborative engineering is currently more of a practiced art than a scientific discipline. A better understanding of how engineers should collaborate with all stakeholders to accomplish complex tasks that fulfill our increasing social responsibilities is a grand challenge. However, because we currently lack well-defined sciences of human collaboration, we must first establish a scientific foundation of collaborative engineering to develop this emerging field into a rigorous discipline. This paper reports on the CIRP community's collective efforts to establish such a scientific foundation according to the "Observation Hypothesis Theory" development pathway. Our objective is to spearhead the rigorous development of this new human-centered engineering discipline, so that useful knowledge can be generated to educate students and practical guidelines can be developed to enable engineers to become more productive collaboration leaders in the new global production industry.