|
|
Cooperative Arrangement
|
Small group of workers (4 dispatchers and 2 supervisors), Location within a site
with co-location at desks. Ability to oversee and overhear one another. Focus on
the use and reconciliation of various screens representing different details of
the deployment of ambulances to incidents across the region. These include:
- Vehicle statuses and placement in the region - the Vehicle Availability Map
(VAM)
- Incident descriptions and details - The Incident Stack
- Information from a Global Positioning Satellite (GPS) system - the Automatic
Vehicle Location System (AVLS)
- Screen for selecting ambulances - Dispatch Selection Screen
|
Representation of Activity
|
|
The focus is on four representations used in the work; the 'Incident Stack', the
'Dispatch Selection Screen', the VAM and the AVLS'. The Incident Stack is a textual
display that shows details of all incidents both waiting to be assigned and active.
The active incidents contain extra information such as the ambulance call signs and
the as-the-crow-flies distance of the ambulances from the incidents (provided by the
AVLS). The Dispatch Selection Screen comes into play when a dispatch operator selects
an incident from the 'Stack'. This screen displays the selected incident as well as a
list of ambulances with the nearest free ambulance highlighted. Selecting an ambulance
on screen forwards the details to that crew. The VAM (see below) is crucial for seeing
what the load is on the service. It displays a series of lists for all the ambulances
in the region. The lists consist of the call signs for ambulances and are placed in a
quasi topological arrangement under abbreviations for areas in the region such that two
consecutive lists correspond to two adjoining areas. Ambulances are highlighted as to
whether they are active, available and so on. The VAM provides a information on both
the status of ambulances and also the current situation by area and as a whole. This
allows workers to see problems developing and to relocate ambulances from quieter areas
to those under strain. These displays are accessible through dispatcher's terminals but
also the Stack and the VAM are displayed on two large monitors. While the AVLS provides
as-the-crow flies distance and the estimated times of arrival (ETAs) to incidents its
display showing ambulances on a map of the region is not (see below) Ambulance control
relies primarily on numerical distance and whether an ambulance is free or not Other
representations are also employed in the assigning of incidents and managing ambulance
control It is the combination of different representations of work that allows dispatch
operators to both make individual dispatch decisions and to observe, manage and plan for
the region as a whole.
|
Ecological Arrangement
|
|
The AVLS is seldom used as a display for understanding the stiuation in
the region while the VAM is crucial for control
|
|
Coordination Techniques
|
|
Coordination is achieved through individual and group orientation to the different
representations of work and other's interaction with them. For example, understanding
the impact of a dispatch decision of another dispatcher as shown on the VAM may
influence the decision as to which ambulance a dispatcher may select from the dispatch
selection screen. As well as coordinating through the system, by comparing and
juxtaposing representations workers explicitly use the multiple representations as
resources for direct verbal interaction in order to discuss enact and plan control
decisions. The display of the VAM and Incident Stack on large monitors allows for
coordination around these two shared representations.
|
Community of Use
|
|
Inter-organisational group of workers (4 dispatchers and 2 supervisors) in an
ambulance control room.
|