JOURNAL OF PUBLIC AFFAIRS EDUCATION - naspaa

Introduction of Government Process Modeling With Rockwell Arena Software
Figure 1.
Model showing the most commonly used Arena modules
with students in the lab and in his office. The first two lab assignments were
intended to help students learn how to use the software and to understand the
meaning of the various “modules” it generates. (See Figure 1.)
As shown in Figure 1, an entire process is composed of multiple (sub)
processes that are represented in Arena by labeled rectangles. Sub-processes also
can be referred to as Activities. A Create module is used to introduce entities
(instances of work to be done) either on a schedule or at time intervals, based on
an exponential distribution. In Figure 1, each new entity passes through an
Assign module, where it can be given attribute values. For example, if the model
represents a process within a hospital’s emergency room, the entities entering the
process are patients, and each patient can be assigned a gender, an age, and a
severity of medical need by use of the Assign module. The Process 1 module in
Figure 1 may represent some kind of necessary admissions activity, followed by a
decision to be made about each entity as it flows through the system. Some of
the entities flow out the “True” branch of the Decide module. All others flow out
the “False” branch of the Decide module. Each entity receives some additional
attention, as represented by the Process 2 and Process 3 modules in Figure 1.
Finally, every entity must eventually exit the system via a Dispose module.
The first lab assignment included specific instructions on how to place
modules on the screen and how to create pathways between them. The intent
was for students to learn to start using the software and to understand the most
basic Arena modules. (See Figure 2.)
The intent of the second lab assignment was for students to learn how to set
parameters within the modules of a process model. When one double-clicks on
a module in an Arena model, a dialog box appears, as shown in Figure 2. The
use of dialog boxes eliminates the need for designers to write instructions as
lines of programming code. In Figure 2, Process 1 is being made into an action
that requires “seizing” the full attention of a clerk for at least a half-hour, and
then “releasing” the resource (a clerk) to be available for servicing another entity.
The time required for one clerk to perform Process 1 for a particular entity is
a triangular distribution, where the minimum required time is 30 minutes, the
maximum required time is 90 minutes, and the most likely required time is
60 minutes.
388 Journal of Public Affairs Education