A new computer simulation tool combines Microsoft Visio's flowcharting
capability and Rockwell Software's Arena simulation tool
to help Army planners ensure that embedded combat service
units remain agile enough to support the
Modular Force effectively.
The Modular Force concept attempts to build brigade unit organizations
supported by a distribution management system with nodes that
are positioned based on mission, enemy, terrain, troops, time
available, and civilian considerations (METT–TC). As
a result, support functions previously accomplished at a single
level have been redistributed and embedded with combat units
to make those units more self-reliant. Although the workload
of these combat service support assets remains the same, personnel
and their equipment have been realigned to allow for greater
autonomy of brigade combat teams (BCTs). Effective combat power
is directly related to the amount of sustainment available
to the maneuver BCTs. This embedded combat service support
must be agile enough that it will not limit the maneuver
Operational performance and capacity planning decisions are often evaluated using
computer simulation techniques such as discrete event simulation modeling, which
is commonly used for analyzing complex systems. This technique creates a simplified
representation of the system under study. It uses Monte Carlo random number and
random variate generation methods
to create sample paths of the system’s behavior. It then experiments with
the simulated system, guided by a prescribed set of goals such as improved system
design, cost and benefit analysis, and sensitivity to design parameters. Experiments
are conducted by generating system histories, observing system behavior over
time, and examining system statistics. The representation created describes system
structure, while the histories describe
Typical deployment and sustainment questions include—
• How much of each supply class will have to be moved? When? By whom?
• What is the capability of the current distribution system?
• What changes are expected to affect the system’s performance?
• How does the distribution system respond under a surge of heavy demand?
• What is the system’s resource availability under various surge
• What alternative courses of action will alleviate shortfalls? What does
The Logistics Research and Development Branch of the Armament Research, Development,
and Engineering Center at Picatinny Arsenal, New Jersey, in partnership with
the Department of Industrial and Systems Engineering at Rutgers, the State University
of New Jersey, developed a means of expanding the simulation modeling capability
by increasing its ease of use and practicality. The project, known as “VisioSim,” aims
at combining the simple flowcharting capability of Microsoft Visio with the simulation
capability of Arena, a simulation tool developed by Rockwell Software. The user
can place procedural and auxiliary information into the model without having
to understand the technicalities of a sophisticated modeling environment. The
flow-charting concept of VisioSim can be used to describe or demonstrate an operational
procedure that may later become part of a bigger simulation model. VisioSim
has been tested successfully by the Center for Army Analysis
to model pierside ship ammunition loading operations at Naval Weapons
Station Earle, New Jersey.
Overview of VisioSim
VisioSim uses the Active X Automation technology and the Visual Basic Applications
programming environment to allow Arena and Visio to communicate with each other.
Data transfer is achieved by using Microsoft Access database constructs to
pass information from one application to another.
Advanced stencils in VisioSim.
VisioSim is intended
primarily for use by subject-matter experts to document “as
is” process flows using basic and advanced flowcharting
objects and to assist modelers in transferring this knowledge
into Arena models to carry out detailed analysis. VisioSim’s
objective is to provide an effective method of transferring
credible workflows between user groups with different functions,
thereby reducing process validation time considerably.
The VisioSim interface is similar in layout to a standard Microsoft Visio template.
Objects with associated dialog boxes are dragged into the model window area to
progressively build workflows. The VisioSim template contains two customized
Visio stencils: Basic VisioSim and Advanced VisioSim (above).
Although the Basic VisioSim stencil incorporates basic Arena modules, such as
Begin, Terminate, Delay, and Process, the Advanced VisioSim stencil includes
the more involved and capable Arena modules, such as Activate, Batch, Separate,
and Match. Both of these stencils are integral parts of VisioSim. Most high-level
processes can be modeled accurately using the Basic stencil; however, the Advanced
stencil is needed to achieve more complex procedures.
VisioSim allows subject-matter experts to document every step of the industrial,
administrative, engineering, and business processes used for design, analysis,
and training purposes in support of Six Sigma lean enterprise analysis. [Six
Sigma is a structured approach to solving complex problems by implementing data-driven
improvement projects. Lean enterprise analysis looks at a business process and
seeks ways to optimize elements of it to make it more productive.] The resulting
value map, the VisioSim chart, is automatically exported to Arena to create a
working Arena model that has a one-to-one relationship with the VisioSim chart.
A simulation modeler gathers various VisioSim charts and exports them into Arena
to merge them into a unified model that simulates the entire system. The resulting
model then can be tailored with specific resource costs, capacities, and purposes
to make the “to be” representation ready for any “what if” analysis.
allows subject-matter experts to document every step
of the industrial, administrative, engineering, and
business processes used for design, analysis, and
training purposes in support of Six Sigma lean enterprise
A Simple VisioSim Model
For demonstration purposes,
we will show how the tasks handled by an ammunition accountable
officer at an
area can be modeled using VisioSim.
Typically, an ammunition accountable officer handles five segments of the
ammunition flow: receipt, shipment to other facilities,
issue to a unit, turn-in of unused
ammunition, and maintenance of ammunition. The ammunition accountable officer
processes the necessary paperwork and sends ammunition and documentation
to other nodes. The chart above shows a VisioSim model
of the procedure the officer
follows in directing ammunition flow. Most of the objects used in the VisioSim
model are Delay and Process objects that represent processing times, Route
objects to send either ammunition or documents, and a Decide object to direct
the traffic. Each object has a dialog box that contains details about the
particular process it represents.
model of the workflows handled by an ammunition accountable
A typical VisioSim study includes descriptions of all the
business processes involved at either the operational level
or a higher level. It may be completed
using operational details that VisioSim provides to produce an operational
flow chart or using VisioSim’s conversion function to produce an Arena
model for a detailed study of the logistics and sustainment issues.
VisioSim provides a structured, well-defined process for capturing the knowledge
of various subject-matter experts. It provides them with the capability to
develop a high-fidelity model suitable for in-depth analysis of the tasks by
capturing this knowledge
and mapping it. For more information on VisioSim and how to obtain it, send
an email to email@example.com. ALOG
Alan Santucci is the Chief of the Logistics Research and Development Branch
in the Logistics Research and Engineering Directorate of the Army Research,
and Engineering Command-Armament Research, Development, and Engineering Center
at Picatinny Arsenal, New Jersey. He has an M.S. degree in computer science
from Polytechnic University in Brooklyn, New York, and an M.B.A. degree from
Dr. Tayfur Altiok is the Chairman of the Department of Industrial and Systems
Engineering at Rutgers, The State University of New Jersey. He has a Ph.D.
in industrial engineering from North Carolina State University.