Developing the Workload Profile
Whilst every tool in the Signaller Workload Toolkit has specific guidance on boundaries of acceptability,
it is important to consider the results of all the tools together. This results in the workload profile.
In developing the profile it may be useful to consider the questions outlined below.
- What are the sources of high demand? What is it that causes them to be a source
of high demand at this location?
- To what extent is the workload a function of the combination of activities that
have to be performed or simply the volume of activities?
- To what extent do the signaller’s actually find the activities demanding?
Information from the Workload Probe can be particularly useful in considering this
question
- What impact do these high demand factors have on:
- The signaller’s ability to maintain attention and their picture of what’s
going on (situational awareness)
- Train performance (for example, are signallers causing delay to trains because they
are experiencing task conflict)
- The signaller’s perceptions of pressure and in particular the extent to which
such the demand factors lead to regular experiences of excessive pressure
- The number of signaller cause irregular working events
- How much of the workload is driven by factors that the signaller has no control
over?
- How do the subjective workload ratings map on to the objective ones? Do peaks in
activity or demands in infrastructure explain peaks in subjective (IWS) ratings?
- How complex is the regulating demand? Consider the factors concerned with :
- Train movements/timetable
- The amount of routes available at each junction
- How frequently the junction is occupied
- Train and line speed (mix of traffic)
- Factors that disrupt the train service: level of perturbation, line blockages, incidents
and occurrences
- Regularity of platform changes
- What are the peaks and troughs in activity and what causes them?
- How long are the peaks in activity? Is the duration excessive, taking into account
how often such a peak occurs and the sorts of activities it might involve? Please
note there are no definitive guidelines about what constitutes excessive activity,
it is a judgement that has to be made.
- What are the cumulative effects of peak periods of activity and/or complexity over
a shift?
- Under peak demands what margins for safety are there in terms of spare capacity
to maintain situation awareness?
- Some of the ODEC scores require a maximum and an average score (i.e., level crossing
use, communications with depots, yards and siding, possessions/line blockages, incidents
and occurrences). Consider what sorts of factors or circumstances create the maximum
score. What implications does this have for a manageable level of workload. How
representative is the maximum score? For example, does it happen once a year, or
every week from April to October, or every day during peak?
- What strategies do signallers adopt to make peak demand times more manageable?
- Are there conflicts in activities where a signaller may be required to be doing
more than one thing at a time? What strategies (such as task re-scheduling or multi-tasking)
does the signaller use to manage this?
- How often do such conflicts occur?
- Are there any demands that require the signaller to focus on one part of the area
of control to the exclusion of others? Are there particular times when this occurs?
- Was there any evidence to suggest that some operations are delayed because of other
tasks that compete for the signaller’s attention?
- What spare capacity is there dealing with inevitable but unplanned, non-routine
work activities such as trains running late, infrastructure failures and incidents
and occurrences? There are no hard and fast guidelines about how much spare capacity
a signaller must have to manage the unplanned events. The following guidelines will
help you to make a judgement about the likelihood of unplanned events so that these
can be factored in or disregarded as unlikely or infrequently occurring.
- Factors to consider include:
- What types of incidents and occurrences happen currently? Are there any patterns?
- Are there particular railway crime hotspots that mean trespass and vandalism events
are a regular event?
- How regular are infrastructure failures? Are there particular locations within the
area of control that regularly fail and cause specific performance issues? Will
infrastructure reliability improve with planned renewals in the near future?
Depending on the purpose of the workload assessment you may be considering the impact
of a change on the workload perhaps because new infrastructure has been added to
the area of control? (e.g. a level crossing or as a result of merging two areas
of control). In such instances questions to consider may include:
- What are the new risks that arise from the changes?
- How do the changes increase and/or decrease the demands on the signaller?
- To what extent can signallers develop new strategies to help them cope successfully
with any new demands?
- What other measures (e.g. training, manning or automation) could be adopted to help
mitigate any risks arising from changes to the signaller’s job?
- How successful are such measures likely to be?