Introduction

5.1.1 Background

Large screen displays (LSDs) play an important role in digital control rooms (CRs) based on desktop-based workstations in the presentation of the essential information of the system. It has been suggested that they could solve some of the main problems caused by digital technology.

Overall, it is supposed that LSDs can support decision making by providing an overview of the state of the process, provide information of important process changes, disturbances and alarms in a way that is easy to detect and identify, help users rapidly move to the place where the essential information is located and support co-operation and collaboration between operators by providing information of what other users are doing (Laarni et al., 2008). By providing an overview of the state of the system they can help users to develop a better mental model of the process. It is said that by this way the LSDs can improve situation awareness both at the individual and at the team level. They can also improve communication and coordination of activities. By means of LSDs users should be able to see how their own actions affect plant parameters that other users are operating. Correspondingly, the LSDs can show them how others’ actions affect those plant parameters they themselves are operating. The LSDs may help users to locate themselves in the information space and tell them by which way they can move from one display page to another. Since more information can be presented at the same time on a large screen, there is less need to scroll the display, open new windows or change the display content. By this way the LSDs should help to reduce the load caused by the secondary tasks.

On the other hand, the design of LSDs for the CR environment is challenging:

For example, since they are qualitatively different from desktop-based workstations, user-interface metaphors developed for small displays are not necessarily adequate in the design of LSDs (Laarni et al., 2008). Integration and consistency with desktop displays is also a challenging issue.

5.1.2 Key design features of the IRD concept

Since LSDs are qualitatively different from other kind of displays, new types of interface metaphors and display concepts – such as Ecological Interface Design (EID) or Function-Oriented Design (FOD) concept – are needed. These concepts are, however, not specifically aimed to the design of LSDs for process industry.

Rapid, easy and accurate detection of changes and failures can be improved, for example, by developing new types of displays that emphasize the essential information by making it more salient and deemphasize the less relevant information by reducing its visibility. Displays based on the Information Rich Design (IRD) concept have been developed by IFE (Institutt for energiteknikk) for those purposes for offshore production facilities (Braseth et al., 2003; Veland

& Eikås, 2007).

The Fortum IRD pilot is the first application of the IRD concept to the design of displays for the monitoring of the nuclear power process. According to the style guide of the Fortum pilot, “the concept refers to data displays that combine the Dull Screen colour principle with analogue coding, integrated trends and layout techniques to obtain high data density without causing information overload” (Braseth et al., 2003, p. 2). Key design principles in their development have been that the visual structure must be simple enough to allow easy scanning, orientation and reading of data-dense displays, and the layout should also provide a sufficiently correct picture of the plant system topology (Braseth et al., 2003; Veland & Eikås, 2007). It is also important that displays can be read by using different strategies depending on the user’s preferences and interests:

they should be useful all along the continuum from a brief glance to a close inspection.

Some of the central aims in the development of IRD displays have been to provide overview information, support early detection of failures and disturbances and help operators to diagnose the problem and stabilize the process. According to Veland and Eikås (2007), IRD displays should reduce working memory demands of operators by providing immediate visual access to frequently used data. By this way they could support the development of an acceptable level of situation awareness based on an overall view of the plant performance. They could also support collaboration and operation and co-ordination of activities within a crew.

The IRD concept is based on such design principles as display normalization, Dull Screen principle and information richness. General requirements for the IRD displays are shown in Table 9. The aim of display normalization is to help users to automatically detect deviations. Two types of normalized symbols have been developed, mini trends and normalized bar-like symbols without mini trends (Figure 19). They support rapid visual scanning of the data by adjusting the mapping between a physical measurement scale and an actual display scale for each data point. As a result, a set of graphs can be grouped together in such a way that small deviations can be immediately detected.

Table 9. General requirements for the IRD displays (Braseth et al., 2004).

1 Avoiding the keyhole effect by aiming for high information density.

2 Providing a wide variety of reading strategies for different tasks.

3 Providing a clear mapping between importance and visual salience.

4 Making the exact value of each data point available.

5 Providing means for simple visual comparisons between different data sets.

6 Supporting pattern recognition by providing means to identify patterns.

7 In the data set as distinct and recognizable.

Figure 19. Normalized trends and bar graphs indicating temperature, pressure, flow, and level (Braseth, 2008).

The aim of the Dull Screen principle is to make the display clearer and prevent visual noise by using specific colouring rules (Van Laar, 2001; Van Laar & Deshe, 2002). According to the principle, essential information is emphasized and less essential information is suppressed. Flicker is not used for alarm purposes, but, instead of that, alarms are indicated by highly saturated colours (red or yellow).

In general, dynamic information is shown by using salient fonts and colours, and information that is less important is presented by low-saturated colours.

IRD displays are dense with information – that is, a lot of information is presented on a small display area. A good example is the presentation of accurate valve position with a special panel in which a lot of information is presented in a small space (Figure 20). Different symbols are used for flow, level, pressure and temperature. The controller output is presented by a vertical bar outside the graph area. The expected position is presented by a diamond and the actual position by a black rectangle.

5.1.3 The starting point for the development of the Fortum IRD pilot As said, displays based on the IRD concept were originally developed for Norwegian offshore petroleum facilities. Some of the IRD displays were presented at HAMBO Group meetings in which they raised interest among the representatives of the group. The HAMBO large screen display project was planned in September 2006, and after that the development of overview displays that are based on the IRD concept were suggested to be included in the HAMBO reference group program. The idea was to study the applicability of displays based on the IRD concept as overall displays in the monitoring of the power process. The main aim was to investigate to what degree they can support the development of an accurate overall picture of the state of the power process and the acquisition of an accurate level of situation awareness (Rinttilä, 2007).

Fortum’s interest in the project is mainly based on the need to replace the old panels and desks project with large-screen overview displays during the Loviisa automation renewal project.

Figure 20. A normalized trend including information of valve position (Braseth, 2008).

Nuclear power companies both from Sweden (Ringhals, Oskarshamn and Forsmark) and Finland (Fortum and TVO) participate in the project. Three prototypes were planned to be developed, one of them at the Fortum development simulator. The other two prototypes have been planned to be designed for Ringhals (units 3 and 4) and for Halden Reactor Group’s (HRP) Hambo simulator. During 2007 it was planned that VTT could participate in the evaluation of the Fortum pilot within the frame of the SAFIR/O’PRACTICE project.

5.1.4 Research method

In the following the results of four types of research activities are presented.

First, we VTT researchers have interviewed designers of the displays, and secondly, observed the design process of the Fortum pilot displays at design workshops. The results of these parts are presented in Sections 5.2 and 5.3.

Thirdly, we have carried out a usability test of the Fortum IRD pilot, and gathered information about users’ experiences and conceptions. The results of

this study are presented under the title “Usability test of the Fortum pilot” in section 5.4. Lastly, we have carried out a heuristic evaluation of the Fortum IRD pilot displays by ourselves. The results of this evaluation are presented under the title “Heuristic evaluation of the Fortum pilot” in section 5.5.