Smart Manufacturing seeks to integrate advanced manufacturing methods, operational technologies (OT), and information and communication technologies (ICT) to drive the creation of manufacturing systems with greater capabilities in cost control and performance. A crucial differentiation of smart manufacturing systems (SMS) lies in their architectures, which are organized as networks of cooperating manufacturing components specialized for different functions as opposed to the previous organization characterized by rigid, hierarchically-integrated layers of application components. This “ecosystem” of manufacturing components enables SMS that can provide heretofore unattainable levels of performance for manufacturers with respect to agility, productivity, and quality. This paper provides a study of the architectural impact of individual ICT technologies on the emerging manufacturing ecosystem that potentially eliminates the need to design manufacturing systems based on the hierarchical levels of the legacy ISA 95 model. Additionally, we propose a service-oriented SMS architecture that leverages the benefits of ICT and the safety and security requirements from the OT domain. Key challenges of implementing such architectures are also presented.