Problem:
Calculating the cost of finding a defect
One of my
peers asked me how I would calculate the cost of finding a bug the other day.
Reason for the quastion was that management was doing a RoI calculation on the
test effort in the project portfolio, and would like to know how much effort (read:
money) they would be spending to find a single bug.
Solution:
Guesstimating based on a few metrics
In nature
knowing the price-tag for finding a defect is interesting, and my answer to the question
was something like this:
Gather some
metrics from your test management tool, test plans, timelogging system or
similar.
Something
like total number of test cases (TC) and defects fount, hours spend on TC
preparation and TC execution
Apply simple
math like:
((hours
spend on TC preparation + hours spend on TC execution)/ total test cases)*
Defect to test case ratio (Defects / TC)
For example:
((442 +
159)/102)*(98/102) = 5,66 man hours / defect.
That excludes
all the cost like test environment cost, training of testers, time spend on
defect management etc.
Happy
guesstimating!
/Nicolai
