New developments in information technologies are radically transforming process automation. Their impact and benefit derive both from these technologies individually and from their convergence in new system architecture concepts. This paper reviews how process automation system architectures have evolved and discusses future trends. We draw an analogy between the synergistic new technologies being developed today and the technology landscape of the early 1970s-characterized by the near-simultaneous appearance of microprocessors, communication networks, CRT displays-that resulted in the first DCS systems (in particular, the Honeywell TDC2000). Emerging technologies highlighted include wireless, embedded devices, service-oriented architecture, and application infrastructures. (c) 2006 Elsevier Ltd. All rights reserved.