Lista de tablas.

During the early 1990s, the Tactical Decision Making Under Stress (TADMUS) programme in the United States of America involved research in support of improved DSS design by in- tegrating cognitive theory and human-machine interaction technology [133]. This programme

attempted, in essence, to design a DSS according to a “naturalistic” modelling approach toward decision-making in environments that are characteristically highly complex, short-fused and dy- namic. The displays were developed to support the decision-making process by addressing the recognition-primed, explanation-based reasoning and cognitive limitations faced by the US Navy officers employed in a Combat Information Centre [148]. This research programme was most likely the foundation for a host of related research that followed.

Figure 7.7: Example of an effective HMI developed through the TADMUS programme [133].

Some of the TADMUS programme’s results have since been declassified, and include discussions on limitations that were present in a preliminary designed DSS [87]. The TADMUS HMI display is shown by Figure 7.7. As my be seen in this figure, the TADMUS DSS is organised into six modules, with different roles to aid the decision-making cycle of the operators:

Geo plot. This display presents the area surrounding the vessel. A desaturated version, with minimal clutter, is depicted by Figure 7.8(a). All detected surface, subsurface and air contacts are overlayed on this screen. The motivation for a 2D display comes from the need to be able to quickly and precisely locate tracks. This module is intended to be the primary focus of the operators and is designed in order to improve the operators’ situation awareness. Symbols of all detected entities are colour and shape coded so as to indicate the status of track identification and TE. Different layers may be “switched” on/off so as to adapt to a particular situation.

Track summary. This screen provides more detail on a selected track. Several flagging-related TE models, such as electronic warfare deployment status and IFF response information, are also displayed on this display. Threat-specific kinematic data are also shown on this display, as shown in Figure 7.8(f).

Track profile and aspect window. This module indicates the speed, altitude, course and range of a single track on a 2D display with altitude on the vertical axis and stand-off range on the horizontal axis, as shown in Figure 7.8(d). The most probable WRL of the threat and the WS ranges of the vessel are also indicated. This module has three main goals: (i) to locate the track’s current position, (ii) to recognise whether the track can engage the vessel and (iii) to recognise whether the track is in range of the vessel’s WSs. Response manager. This module is responsible for assisting the operator in delegating pre-

planned responses against the selected threat. An example of this display is shown by Figure 7.8(b). Possible responses are graphically depicted in a Gantt chart type display

7.4. HMI Design Considerations 127

(a) Integrated geo plot (b) Response manager (c) Mini-CRO

for single track

(d) Track profile with engagement pos- sibility

(e) Basis for assessment (f) Track summary

Figure 7.8: Different TADMUS HMI modules in the large display of Figure 7.7.

on the screen so as clarify their aims. A vertical line also indicates the threat’s current position relative to the vessel. Furthermore, this display serves as a graphical embodiment of the current ROE and doctrine. This module, essentially, attempts to support a story telling approach to decision-making.

Basis for assessment. This module, shown in Figure 7.8(e), is an expert system which em- ploys expert-based reasoning to add value to the current available information. The pre- sented information provides the operator with a means to criticise his or her decision- making process with a view to improve the quality of the selected response.

Character read-outs. A series of Character Read-Outs (CROs) are displayed across the bot- tom of the display, as shown in Figure 7.7. These displays only indicate critical track information, such as track-number and aircraft type. Several contacts are focussed on si- multaneously in this display. Contacts are prioritised according to the level of danger they pose to the vessel. Consequently, the order of the CROs change throughout the scenario, thereby allowing operators to prelude attention to the changes in priority.

These modules are, essentially, arranged in order of increasing information integration from the top to the bottom. The first three modules, namely the track summary, the track profile and geo-plot, which all analyse a specific threat, are located at the top of the display. The response manager and basis for assessment which, on the other hand, deal with the evaluation of possible responses, are located at the middle of the display. The CROs module, which present information on all the threats, is displayed at the bottom of the larger display.

According to the results of the TADMUS program [133], decision-makers (operators) seem to use a “stepping-stone” approach to reach a decision on which to act — available information is used in order to reach a consensus regarding the priority of a track, after which other information

sources are explored to ascertain further implications for that specific threat, given its assumed priority.

Better supporting such a decision-making process by, for example, by increasing the OPTEMPO of the OODA cycle, should allow the operators more time to coordinate responses. A possible means to achieve this is to a certain extent automate the first step of the “stepping-stone” strategy (prioritisation of threats). The TE subsystem described in Chapter 5 serves the purpose of automating this step. The flagging models may then be used in conjunction with other threat- specific information to decide on an appropriate course of action (e.g. engaging threats, sending warnings, employing electronic warfare capabilities or attempting to deter the threat).

Before determining whether this DSS is indeed fit for use in a GBAD environment for TEWA purposes, it is suggested that a Work Domain Analysis (WDA) is applied. A WDA was suc- cessfully applied by Burns et al. [31] to evaluate the suitability of the TADMUS DSS (which was designed for a US naval environment) to the C2 of the Canadian HALIFAX class frigate9_. WDA is a generally applied technique for the design of new DSS; it has even been proposed to be used for evaluating possible acquisition projects. Nonetheless, some of the TADMUS HMI modules should prove to have some residual capability in the context of a GBAD environment.