Input modeling with the Johnson System of distributions

This paper provides an introduction to the Johnson translation system of probability distributions, and it describes methods for using the Johnson system to model input processes in simulation experiments. The fitting methods based on available data are incorporated into the public-domain software package FITTR1. To handle situations in which little or no data is available, we present a visual interactive method for subjective distribution fitting that has been implemented in the public-domain software package VISIFIT. We present several examples illustrating the use of FITTR1 and VISIFIT for simulation input modeling.