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A New Tool for Simulation
Modeling of Logistics Support


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 support 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
commander’s flexibility.

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
system behavior.

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 scenarios?
• What alternative courses of action will alleviate shortfalls? What does each cost?

VisioSim

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 and has been used 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.

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.

Six Sigma

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.

A Simple VisioSim Model

For demonstration purposes, we will show how the tasks handled by an ammunition accountable officer at an ammunition storage 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.



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 alan.santucci@us.army.mil. ALOG

Alan Santucci is the Chief of the Logistics Research and Development Branch in the Logistics Research and Engineering Directorate of the Army Research, Development, 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 the University of Phoenix.

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.