# {8 d; u, t8 ]+ F* GMost useful feature would be ability animate and step through the simulation, observing entity movement and clock time. Also the ability of Arena and GPSS to collect statistics would have helped. The time to develop the model would have been much less than what it did take. Having a graphic or block oriented model could also help insure the model was a reasonable representation of the system. Computer code is readable only by programs. Arena and GPPS can be read (viewed) by non programmers.