Triangular
Distribution
The Triangular distribution is applied to continuous random
variables. The Triangular distribution is usually shown with a skew to one side
or the other. The Triangular distribution portrays the situation that not all
outcomes are equally likely as was the case in the Uniform distribution. The
Triangular distribution has finite tails that meet the horizontal value axis at
some specific value.
There is little in nature that has a Triangular distribution.
However, it is a good graphical and mathematical approximation to many events
that occur in projects. Project management, like engineering, relies heavily on
approximation for day-to-day practice. For instance, the approximate behavior of
both cost work packages and schedule task durations can be modeled quite well
with the Triangular distribution. The skew
shows the imbalance in pessimism or optimism in the event.