KEYNOTE
”Implementation of human factors analysis in QRA and SRA”
Ove T. Gudmestad1, 2 and Roger R. Stølsnes2, 3.
1. Statoil, Stavanger, Norway
2. Stavanger University College, Stavanger, Norway
3. Holte Prosjekt, Oslo, Norway
Abstract
Qualitative and Quantitative Risk Analysis are carried out to identify potential risks in the
execution of a project (in the temporary phases of the project) or during operations of an
industrial plant. While Qualitative Risk Analysis mainly will identify potential risks, making
it possible to prepare actions to avoid the consequences of the probable risky situations,
Quantitative Risk Analysis are considered more fit to rank the potential risks and put
emphasis on situations that could lead to the highest risks. It may also be possible to carry out
cost benefit analysis to identify the cost effectiveness of taking remedial actions.
Human factors are taken into account as far as one can identify whether “tasks” are
particularly prone to the human element (stress, aging, tiredness, etc.). The effects an
organisation has on the human elements and then on the outcome of a QRA are, however,
normally not accounted for. Such effects could be caused by a poor working climate in the
organisation, by unclear messages from the management and even by the partial lack of the
management function. Neither is normally the stress caused by unrealistic schedules or
budgets taken into account nor the effects of an organisation where “upward licking and
downward kicking” is the normal way of working. We have seen large failures in such
organisations, e.g. in NASA with the US Space Shuttle Programme, where the messages from
engineers have been blocked from reaching management. Organisations where “whistle
blowers” are required to wake up management do suppress identification of problems and are
thus much more prone to risks.
We will discuss how it will be possible to implement the human factor elements in Qualitative
and Quantitative Risk Analysis and give some guidance as to key elements that we think
would deteriorate the performance of humans and organisations particularly making the
organisations susceptible to risks in execution of projects or operations of plants. It should be
notes that the term “risk” in this context refers to risks to personnel and environment as well
as to risk to (probability of loss of or damage to) assets and risk of cost and schedule overruns
in projects.
In Structural Reliability Analysis (SRA) it is never customary to implement thoughts about
“the human factors”. One has here to do with issues that could easily be quantified, as the
spread in the quality of steel plates. Due to this confidence in data, one can well miss
systematic and serious errors that in most instances can be attributed to human elements.
Although it never will be possible to dimension structures against gross errors in the design or
fabrication phase or stupid lack of knowledge, it could be possible to identify such errors that
will influence the SRA by carrying out hazard identification reviews of a project.
Furthermore, tests to ensure that gross errors are not present in the data, and requirements to
education and experience for those involved in the project may help to avoid the results of
gross errors.
The tendency in all engineering disciplines to get rid of experience and to hire young
graduates with computer skills is extremely worrying as the results of an analysis may give an
indication of a careful work, even if the result is a digit off the true value. In this respect an
SRA without a review of experienced personnel could give a very misleading impression. It
should be noted that identification of tails in the input distributions do require particular skills
and that some engineers may not see potential problems while the “Devil’s Advocate” may
not be let into the project. An example of the consequences of shifting computer software
while not giving staff time to familiar itself with the new (and cheaper) software will shed
light on these aspects.
Concluding, we are mainly concerned with the organisational aspects leading to human
failures not normally implemented in QRA`s and SRA`s. We strongly suggest that these
aspects shall be taken into account in QRA`s and that SRA`s must be followed up with hazard
identification reviews to be adequately reliable.