On complexity reduction of user interfaces for safety-critical systems

Abstract

Control and communication systems used at power plants or incineration facilities offer various graphical visualizations of the physical parts of the site; however, they rarely provide sufficient visualization of the signal data. There is the problem, that such facilities contain 10,000 or more data acquisition points; each of them continuously sending data updates to the control system (once in 20 ms or less). This huge load of data can be analyzed by a human expert only if appropriately visualized. Such a visualization tool is AutoDyn, developed by the company Technikgruppe, which allows processing and visualizing complex data and supports decision making. In order to configure this tool, a user interface is necessary, called TGtool. It was originally developed by following a system-centered approach, consequently it is difficult to use. Wrong configuration can lead to incorrect signal data visualization, which may lead to wrong decisions of the power plant personnel. An unintentional mistake could have dramatic consequences. The challenge was to re-design this tool, applying a user-centered approach. In this paper we describe the re-design of the configuration tool, following the hypothesis that a user-centered cognitive map structure helps to deal with the complexity without excessive training. The results of the evaluation support this hypothesis. © 2012 IFIP International Federation for Information Processing.