UNEXPLODED ORDNANCE - Wind Energy Network

RISK MANAGEMENT
Figure 3: “Tiger in Cage” Bow-Tie
So where do Bow-Ties fit in
Bow-tie diagrams can be generated for
every hazard identified for any particular
operation at any point in its life cycle.
However, it is clearly not appropriate,
efficient or cost effective to construct
diagrams for all identified hazards. Bowtie
diagrams are most commonly used,
and realise the largest benefit in analysing
major hazards.
The Risk Assessment Matrix, discussed
in a previous issue (see February/March
2012), can be utilised as a “screening” tool
to identify major hazards requiring further
investigation, with bow-tie diagrams clearly
identifying the controls/mitigations against
such hazards.
Limitations of the Bow-Tie Method
Of course bow-ties are not the panacea
for all risk management problems. If
you want to quantify your level of risk in
absolute terms then the bow-tie method
will not help directly. Similarly, if you want
to model complex inter-relationships
between your risk controls, there are
better ways than using bow-ties.
As with all risk assessment techniques,
the quality of the information output is
dependent on the quality of the individuals
leading the workshops/assessment and
the team assembled to assist. The danger
exists that, due to the apparent simplicity
of the bow-tie diagram, such assessments
are undertaken by inexperienced
personnel and without the direct input
from all involved parties (operations,
maintenance etc.). In such a scenario,
bow-ties could be generated which do not
represent the on-site operations and omit
key threats, consequences or controls.
In summary, a number of differing
techniques are available for assessing
risk. However if you want to remove
the mystique of risk management and
obtain insights into your risk controls
that are easy to understand and easy
to communicate, then there is no better
method than bow-ties.
James Sneddon
Risktec Solutions Ltd
www.risktec.co.uk
Click to view more info
www.windenergynetwork.co.uk
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