A Review of the Event Analysis of Systemic Teamwork Methodology

HFIDTC/WP1.1.3/10
Version 2/ 31 October 2005
• The reliability of the technique is questionable. Different analysts may
interpret the OSD symbols differently.
Related methods
Various types of OSD exist, including temporal operational sequence diagrams,
partitioned operational sequence diagrams and spatial operational sequence diagrams
(Kirwan & Ainsworth 1992). During the OSD data collection phase, techniques such as
observational study and interviews are typically used. Task analysis techniques such as
HTA are also used during the construction of the OSD. Timeline analysis may also be
used in order to construct an appropriate timeline for the task or scenario under analysis.
Additional analyses results can also be annotated onto an OSD, such as CDA and comms
usage diagram. The OSD technique has also recently been integrated with a number of
other techniques (HTA, observation, co-ordination demands analysis, comms usage
diagram, social network analysis and propositional networks) to form the event analysis
of systemic teamwork (EAST) methodology (Baber et al 2004), which has been used to
analyse C4i activity in a number of domains.
Approximate training and application times
The training time associated with the OSD methodology is low. However, the typical
application time for the technique is high. The construction of an OSD can be a very time
consuming process, involving many re-iterations. A typical OSD normally can take 12 +
hours to construct.
Reliability and validity
According to Kirwan & Ainsworth (1992), OSD techniques possess a high degree of face
validity. The intra analyst reliability of the technique may be suspect, as different
analysts may interpret the OSD symbols differently.
Tools needed
When conducting an OSD analysis, pen and paper could be sufficient. However, to
ensure that data collection is comprehensive, it is recommended that video or audio
recording devices are used in conjunction with the pen and paper. For the construction of
the OSD, it is recommended that a suitable drawing package, such as Microsoft Visio
is used. The WESTT software package can also be used to automate a large portion of the
OSD procedure. WESTT constructs the OSD based upon an input of the HTA for the
scenario under analysis.
Example
The following example is an extract of an OSD of an energy distribution scenario
(Salmon et al 2004b). The task involved the switching out of three circuits (SGT5 and
SGT1A and 1B) at Barking 275Kv, 132Kv and 33Kv Substations. Circuit SGT5 was
being switched out for the installation of a new transformer for the nearby channel tunnel
rail link and SGT1A and 1B were being switched out for substation maintenance.
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