POWER June 2016 - 18

Use Near-Miss Incidents
as a Preventive Tool
Broadly put, today's power plant operations
are a mix of automated operations
and manual or procedural steps. A plant
may have hundreds of control loops, interlocks,
permissives, and safety systems.
In addition, there are procedural steps,
which rely on operator interaction, such
as opening or closing a valve, slow rolling
a turbine, or taking grab samples. In
view of the large number of operations,
it appears reasonable to anticipate that
something will go wrong someday.
In those instances when something does
go wrong, the result is not always a major
incident; sometimes the outcome is just
a close call. Management tends to have
mixed feelings about these near misses. On
the one hand, they breathe a sigh of relief
that the result of the incident was not more
serious. On the other hand, they worry that
their current system may be ill prepared to
deal with a similar incident in the future.
Evaluating Near Misses
The causes of unwanted events could be
many. Some examples include:
■ Aging plants and control systems
■ Outdated or inadequate procedures
■ Inadequate training
■ Workforce turnover
■ Impact of business climate-divestitures
and acquisitions
■ Plant systems inadequately designed
for severe weather conditions
Many experts suggest that near-miss incidents
are opportunities in disguise. They
believe that close calls can be used to prevent
future incidents. Most power plants
conduct some sort of root-cause investigation
after near-miss incidents. Depending
on the findings, managers may pursue
one of the following courses:
■ Take no action, if the incident was
deemed only " minor. "
■ Install additional safeguards to prevent
similar incidents in the future, if the
incident had the potential to have a
major impact.
In many cases, shift leaders, project
managers, or groups of in-plant subject
matter experts determine subjectively
whether an incident is " minor " or " major. "
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They typically rely on their personal experience
to make that decision. This can be a
reasonably effective approach for categorization
of near-miss incidents; however,
in some cases it can lead to inaccurate
assessments. The following points may be
worth considering relative to the consistent
effectiveness of that approach:
■ Often, shift leaders and project managers
are under intense pressure to accomplish
myriad projects in relatively
short timeframes. Time scarcity can
result in hasty near-miss classification
decisions.
■ The approach is often based solely on
the severity or potential severity of an
incident. This method frequently fails
to evaluate the likelihood of a future
incident. For that reason, it is possible
that this approach might overlook incidents
with a medium level of severity
but a high likelihood of occurrence.
The Risk Matrix Approach
A risk matrix technique may offer a more
reliable solution. The process uses a
semi-quantitative technique to identify
near-miss incidents that could become
sufficiently severe with unpleasant consequence
under a slightly different set of
circumstances. The following steps outline
how the system works:
1. Evaluate each near-miss incident without
haste while remembering that the
ultimate goal is to reduce risk to workers,
neighbors, and the environment.
2. For a given near-miss incident, estimate
and index its likelihood and potential
severity (consequence) on the matrix
shown in Figure 1, using the criteria
described in Table 1.
3. Once risk has been estimated, take appropriate
corrective actions to prevent
or minimize the recurrence of such an
event.
1. Risk matrix for near-miss incident management. This matrix can be used to
index incidents by severity and likelihood rank (see Table 1). Source: GC Shah
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Likelihood
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Severity
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POWER June 2016

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