A Review of the Event Analysis of Systemic Teamwork Methodology

HFIDTC/WP1.1.3/10
Version 2/ 31 October 2005
3.7 Operation Sequence Diagrams
Background and applications
Operation Sequence Diagrams (OSD) are used to graphically describe the activity and
interaction between teams of agents within a network. According to Kirwan and
Ainsworth (1992), the original purpose of OSD analysis was to represent complex, multiperson
tasks. The output of an OSD graphically depicts the task process, including the
tasks performed and the interaction between operators over time, using standardised
symbols. There are various forms of OSD’s, ranging from a simple flow diagram
representing task order, to more complex OSD which account for team interaction and
communication. OSD’s have been applied in a number of domains, including the fire
service (Baber et al 2004), naval warfare (Stewart et al 2004), aviation (Stewart et al
2004), energy distribution (Salmon et al 2004), air traffic control (Walker et al 2004) and
rail (Walker et al 2004) domains.
Domain of application
The technique was originally used in the nuclear power and chemical process industries.
However, the technique is generic and can be applied in any domain.
Procedure and advice
Step 1: Define the task(s) under analysis
The first step in an OSD analysis is to define the task(s) or scenario(s) under analysis.
The task(s) or scenario(s) should be defined clearly, including the activity and agents
involved.
Step 2: Data collection
In order to construct an OSD, the analyst(s) must obtain sufficient data regarding the task
or scenario under analysis. It is recommended that the analyst(s) use various forms of
data collection in this phase. Observational study should be used to observe the task (or
similar types of task) under analysis. Interviews with personnel involved in the task (or
similar tasks) should also be conducted. The type and amount of data collected in step 2
is dependent upon the analysis requirements. The more exhaustive the analysis is
intended to be, the more data collection techniques should be used.
Step 3: Describe the task or scenario using HTA
Once the data collection phase is completed, a detailed task analysis should be conducted
for the scenario under analysis. The type of task analysis is determined by the analyst(s),
and in some cases, a task list will suffice. However, it is recommended that a HTA is
conducted.
Step 4: Construct the OSD diagram
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