Location within a site. Arrangement into 16 suites. Small group of workers per suite (2 controllers, 2 assistants, 1 sector chief), co-location at a suite. Ability to oversee and overhear one another. Focus on one type of artefact, flight progress strips, how they are constituted and how they are displayed, amended and oriented to in this setting.
Various details about a scheduled plane journey, including, flight level, destination, radio code and planned flight path, flight number and airline, are represented by the individual flight progress strips. Furthermore, details of changes to the flight details are recorded on the strip itself while maintaining a record of what they have been changed from by whom, why. This is achieved through scoring out previous details amending and check marks. Any one of the workers may amend the strips, each using a different coloured pen to identify their annotations. This allows controllers to recover the 'trajectory: a sense of what they have done with a flight, how (and why) they reached the current situation' On a larger scale the arrangement of the series of flight progress strips on the wall represents the current status of the control sector, with the progress of a flight strip across the board being indicative of a plane's progress across the airspace. Importantly, also, strips are 'cocked out' of their placement on the slots on the wall to indicate that they may be problematic.
Flight progress strips and co-ordination around display of strips are crucial to control.
Coordination is achieved through the flight strips themselves. Co-workers can be made aware of the work of others in changing the details and therefore the flight path of planes through the recording of these via coloured pens and initials on the strips. Their placement on the wall serves as a means to coordinate activity of the group of control workers. Problem strips are highlighted to the group by 'cocking them out' from their placement on the wall. The workers can point to and discuss different aspects of the airspace through the arrangement on the wall. This facilitates teamwork and group resolution of problems.
Inter-organisational group of workers in the air traffic control room.