Qualitative Project Risk Analysis
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What do you
mean by probability and severity scales, and how do I use them?
Assessing Probability
Probability
is best assessed on a five point scale as follows:
1. Highly unlikely: p = 0.1
2. Unlikely: p = 0.3
3. Possible: p = 0.5
4. Moderately probable: p = 0.7
5. Highly probable: p = 0.9
Assessing Severity
Severity is
also best assessed on a five point scale as follows:
1. Insignificant: s = 0.05
2. Moderate: s = 0.10
3. Medium: s = 0.20
4. Severe: s = 0.40
5. Catastrophic: s = 0.80
·
Note the ratio scale
The Risk Event Status or Rating
Matrix
Red = serious concern; Grey = concern; Green = awareness

Assessing
Probability
·
Strive for range, not accuracy!
·
Ask Questions like:
·
Are our chances above or below 50%?
·
If above (below) better than 90% (worse
than10%)?
·
If below 90% (above 10%) then above or
below 70% (30%)?
·
Donít ask "What is the longest time this
activity could take?"
·
The inevitable answer will be "Forever"!
·
Deal with the Impact scale the same way
·
Except note that it is a ratio scale, not
linear
Other techniques
- 1
Testing the
project's assumptions
·
Your project does have a list of
assumptions, I hope?!
·
Test them against two criteria:
·
Stability: How true will the assumption
remain through the project life span?
·
Consequences: What if the assumption
proves to be false?
·
Alternative assumptions should also be
identified
Other techniques
- 2
Data precision
review
·
Qualitative risk analysis requires
reliable and unbiased data
·
If the result is to be meaningful
·
Evaluate the data against the following
criteria
·
Extent of understanding of the risk event
·
Availability of data, how much do we
really know?
·
The quality of the data we have
·
Its reliability and integrity
Beware of the
Fatal Flaw!
·
Always watch out for the risk event with
the "fatal flaw"
·
It may look very unlikely
·
But it could be devastating!
·
A "fatal flaw" project risk event is one
that presents a situation that simply cannot be recovered
·
The technology proves to be inappropriate
·
A key knowledge worker moves on
·
Political climate changes dramatically
and so on.
. .
What have we
accomplished?
You should end up
with:
·
An overall risk ranking for the project
·
Perhaps as a basis for proceeding further
·
A prioritized list of project risks
·
For closer scrutiny, perhaps for
association with scope, quality, time, cost or functionality, etc
·
Priority risks for further analysis
·
I.e. Quantitative Risk Analysis