Syntax: Erl(mean, shape, stream)
The Erlang distribution (continuous) could be used to model the time required to perform some task. If an Erlang distribution has parameters mean = m and shape = a, then b = m/a is a scale parameter. An Erlang distribution is just a gamma distribution whose shape parameter is a positive integer. The sum of k exponential random variables with mean = m is an Erlang distribution with mean = km and shape = k.
Stream allows you to specify the random number stream for the distribution. There are 215 streams. Stream 1 is the default. See Seeds or Appendix D of the User's Guide for more information.