Conceptual design of industrial process displays

Today, process displays used in industry are often designed on the basis of piping and instrumentation diagrams without any method of ensuring that th e needs of the operators are fulfilled. Therefore, a method for a systemati c approach to the design of process displays is needed. This paper discusse s aspects of process display design taking into account both the designer's and the operator's points of view. Three aspects are emphasized: the opera tor tasks, the display content and the display form. The distinction betwee n these three aspects is the basis for proposing an outline for a display d esign method that matches the industrial practice of modular plant design a nd satisfies the needs of reusability of display design solutions. The main considerations in display design in the industry are to specify the operat or's activities in detail, to extract the information the operators need fr om the plant design specification and documentation, and finally to present this information. The form of the display is selected from existing standa rdized display elements such as trend curves, mimic diagrams, ecological in terfaces, etc. Further knowledge is required to invent new display elements . That is, knowledge about basic visual means of presenting information and how humans perceive and interpret these means and combinations. This knowl edge is required in the systematic selection of graphical items for a given display content. The industrial part of the method is first illustrated in the paper by a simple example from a plant with batch processes. Later the method is applied to develop a supervisory display for a condenser system in a nuclear power plant. The differences between the continuous plant doma in of power production and the batch processes from the example are analyse d and broad categories of display types are proposed. The problems involved in specification and invention of a supervisory display are analysed and c onclusions from these problems are made. It is concluded that the design me thod proposed provides a framework for the progress of the display design a nd is useful in pin-pointing the actual problems. The method was useful in reducing the number of existing displays that could fulfil the requirements of the supervision task. The method provided at the same time a framework for dealing with the problems involved in inventing new displays based on s tructured analysis. However the problems in a systematic approach to displa y invention still need consideration.