The increasing complexity of chemical processes, in terms of technological involvement, intensified with automation, has made the role and job of industrial operators more significant in terms of Process Safety. This work takes the concept of Distributed Situation Awareness (DSA), introduced by Stanton et al. (2006), and presents its application, adaptation, and influence on the process industry in general and on industrial operators in particular. DSA considers the importance of viewing the system as a whole by considering all the parts in the environment. The combination and interaction of different elements including field operators, control room operators, the artifacts with which they interact with each other and with different bits of information/data, and the communication among them are the basis on which the DSA of industrial operators founds. The decisions made by the operator are not only based on his/her understanding and mental model but they include the whole system. The paper shows how studying the operator as an individual only is not sufficient. Conversely, a holistic approach allows gathering most of the nuances of complex systems as the industrial plants are. A measurement method for DSA is proposed and a case study, i.e., a refinery sub-section, aimed at identifying and devising specific DSA indicators, is presented. This work can help in reducing abnormal situations, near misses, and accidents arising from errors related to operators and their interaction with other operators and with various elements of the process industry.