Two workers (divisional information assistant (DIA) and line controller). Located within a site, co-located at desks. Ability to overhear and oversee one another. Focus on the collaborative techniques personnel use to achieve underground train control and management.
The teamwork of the DIA and line controller has no explicit representation. However, representations and interaction with them form some of the basis for the teamwork carried out. For example, most noticeably, the shared representation of train progress, the fixed line diagram, serves to coordinate activity. When a controller looks at this, points to features or so forth the other can clearly pick up what is going on an act in accordance with this. Similarly the results of teamwork are recorded in the changes to the representations, whether these be timetables, or artefacts depicting train operation.
The line controller and DIA sit beside each other at a console of paired displays (blue arc) for each, e.g. CCTV and train describers. A fixed line diagram, where lights are activated according to trains progress serves as a single shared artefact (yellow bar) in front of them.
The two workers primarily collaborate by monitoring one anothers activity. When one carries out a particular task the other will initiate an activity in response to what has just been done. For example, when the line controller makes a change to the trajectory of a particular train the DIA will announce this to passengers. Interestingly this is done in a very concerted and economic manner with little actual conversation between the two. In order to make this easier they project or make their activities more visible, for example, by noticeably staring at artefacts or raising their voices. This requires that the personnel continually monitor one anothers work.
Inter-organisational pair of workers (line controller and DIA) in a London Underground control room.