Integration aspects in automation - a technology survey

"Integration", in particular vertical integration, has become one of the dominating buzzwords in the automation business. While marketing campaigns mostly in the context of industrial Ethernet and modular manufacturing execution systems evoke the impression that integration in automation is a new and revolutionary concept, the opposite is true: integration has always been the ultimate goal of automation. This article presents the historical roots and their evolution up to the present day. Furthermore, it proposes a model describing the three essential aspects of integration, namely, horizontal, vertical, and temporal, and gives an overview of the current technological building blocks such as networks, middleware, and application concepts. Open problems and future challenges in the area are discussed as well