How we manage our scrap events
determines whether our business thrives or dies. Consider a policy to start absolute-lot quantities,
which means, no extras, ever.

In the October 2012 issue of The PCB Magazine, Gray MacQuarrie, president of Grayrock & Associates, uses ExtendSim to illustrate the option of restarting jobs
in which you start absolute-lot quantities—no extras—even though this requires disciplined execution and a tightly timed and reliable production
process. This option could make your operation extremely profitable—if you can do it. Learn more.

Does it really make sense to roll
the dice with an important customer order, just because of the inherent unreliability of your metal finishing operation? If so, it may be time for you to change the game—today.

In the October 2012 issue of The PCB Magazine, Gray MacQuarrie, president of Grayrock & Associates, introduces an ExtendSim model that could be used to illustrate cost to a business when a worst-case scenario happens and how you could best handle the situation with your customer. Learn more.

In the August issue of The PCB Magazine, Gray MacQuarrie, president of Grayrock & Associates, uses ExtendSim to illustrate that "as you improve your scrap rate you can reduce the delivery time on quick-turn lots, which may allow you to earn a higher performance premium." Learn more.

Success in your first simulation model is crucial for the overall prospects of a new simulation program. This paper outlines the building of your first simulation model with emphasis on the overall process and what it takes to be a successful model builder.

Simulation models are typically built to obtain an understanding of the system dynamics and compare alternatives. ExtendSim’s Scenario Manager provides an easy interface to evaluate different model configurations and explore the effects of model parameters. Scenario management provides for a systematic, controlled approach to the investigation of a system or process. Among other things, it can be used for problem solving ("what are the main factors contributing to the problem"), parameter design ("how well does the system/process perform given specified factors"), and robustness studies (what is the best configuration of factor values to maximize/minimize variations in response".) Thus it has a very broad application across all disciplines.

Each month, Simulation magazine features a different simulation application on its cover. In August 2000, a model of an airport security checkpoint was selected.This model utilized Extend bundled with Proof Animation (Extend Suite) to simulate and animate proposed changes to an existing security system.

This paper explores two approaches to modeling manufacturing queueing systems: traditional discrete-event modeling and the agent-based approaches.

This paper describes a flexible architecture for modeling thousands of autonomous agents simultaneously. The agents' behavior is based on a subsumption architecture in which individual behaviors are prioritized with respect to all others. The primary behavior explored in this work is a group formation behavior based on social potential fields. It extends the social potential field model by introducing a neutral zone within which other behaviors may exhibit themselves.

The Department of Homeland Security (DHS) shifted the focus of airport security in 2004 to incorporate the need to continuously and rapidly adapt security to shifting threats. MITRE is developing a Dynamic Security Airport Simulation as part of a MITRE-sponsored research project in which attacker and defense behavior in the airport environment are modeled. The simulation accepts threat vectors (path-weapon combinations) from other software or the user and models the performance of the airport defense against those threat vectors. The simulation includes two intelligent agents: the attacker and the defense. These agents model the behavior of those two entities; their logic includes both decision making and learning.The simulation includes two intelligent agents: the attacker and the defense. These agents model the behavior of those two entities; their logic includes both decision making and learning.

Learn more about Mitre's project here.

 

Report compiling information about progress in the application of simulation to planning and management of recreation use, particularly in parks and wilderness. The bulk of this report consists of case studies that illustrate a broad array of recreational situations and management applications for simulation modeling.

This paper describes the framework development of a dynamic integrated biomass supply analysis and logistics model (IBSAL) to simulate the collection, storage, and transport operations for supplying agricultural biomass to a biorefinery. The model built in Extend consists of time dependent events representing the working rate of equipment and queues representing the capacity of storage structures. Weather conditions including rain and snow influence the moisture content and the dry matter loss of biomass through the supply chain are included in the model.

This case study demonstrates the value of simulation modeling in the healthcare architecture design of a new ambulatory surgery unit. The simulation developed explores the relationship between the number of operating rooms and recovery beds, the number of cases and the phases of recovery, bed capacity, staffing, and waiting room seat requirements as each affected the design. Model results allowed time for variations in the design to meet the client's needs before the project was built. Furthermore, the simulation shows the positive outcome of combining the experience of three professional disciplines: healthcare planning, architecture, and simulation modeling for nurses, doctors and patients of the new ambulatory surgery unit.

In a 3-year project funded by FCS Research through United States Military Academy, Innovative Decisions, Inc. created a Dynamic Decision Network (DDN) utilizing ExtendSim in conjunction with other software tools. The DDN created is a combination of an influence diagram and a Bayesian network that addresses specific problems.

Biofuels are transport fuels made from organic material. The most common biofuels today are biodiesel (made from vegetable oils) and bioethanol (made from sugar and starch crops). Research is under way to commercialize “second-generation” production techniques that can make biofuels from woody material, grasses, and some additional types of waste. Biofuels have a unique role to play in European energy policy. They are today the only direct substitute for oil in transport that is available on a significant scale.

This paper that was originally presented at the 7th International Scientific Conference on Engineering for Rural Development in May of 2008 in Jelgava, Latvia. It provides a short overview of the strategies and action plans in production and use of biofuels in Europe and Latvia. Then, existing solutions in the
improvement of biofuel logistic systems are analyzed as well as ExtendSim as a tool for the modeling of biofuel supply chains.

As biotechnology organizations have successfully launched new products, the challenges of producing adequate quantities have grown. Simulation is a powerful tool that can offer many benefits if done right and used appropriately. This general overview compares static and dynamic modeling and their usefulness in the biotechnology field.

This paper aims to raise awareness about the usefulness and importance of simulation in support of software engineering. Features an Extend model that depicts a call-center type of process for a computer security incident response team.

Case study in which a simulation project manager wanted to determine current plant capacity and be able to test the effects of various changes. This article discusses models that examined the balance between the "making" and "packing" systems during an annual production cycle.

Simulation: Operations Excellence Tool in Lean Manufacturing is a good overview paper on the use of ExtendSim in lean manufacturing. Defines simulation and highlights a few areas where it can be most valuable.

This case study presents multi-product batch optimal scheduling using Resource-Task Networks (RTN). This combined approach of discrete event simulation and deterministic optimization has provided rapid improvements in the scheduling technology.

This paper discusses a discrete event simulation model developed to identify and understand the impact of different failures on the overall production capabilities in a chemical plant. The model is designed to be used to understand key equipment components that contribute towards maximum production loss and to analyze the impact of a change policy on production losses. A change policy can be classified in terms of new equipment installation or increasing the stock level for the failure prone components. This paper presents the approach used and some preliminary results obtained from available data.

In NCW End-To-End (NETE) Model For Future C2 Architecture Assessments, NETE -- a Net-Centric Warfare (NCW) End-to-End model is discussed. NETE is a medium fidelity constructive simulation of the Global Information Grid (GIG) infrastructure, Service networks, and their integrated operations in support of definable mission areas. The NETE model provides a means to assess the ability of a defined network to support a concept of operations with resource management to allow the assessment of latencies under varying loads. SPARTA has established this model across their corporate communications infrastructure; populating databases with hundreds of gigabytes of data, simulating user loads using distributed simulations to drive loading, and emulating sensor feeds while viewing geometries and sensor propagation.NETE also calculates the impact of network ‘jitter’ on mission timelines.

Simulation Streamlines Production, Shaves Cost describes a digital wireless communications products and technologies manufacturer that streamlines its equipment manufacturing processes and improves inventory control, generating significant cost savings, with simulation.

This paper applies DOE and broad range sensitivity analysis to a Hybrid System Dynamics and discrete event simulation model of a software development process. DOE is used to analyze the interaction effects, such as the degree to which the impact of the process change depends on worker motivation, schedule pressure and other project environmental variables. The sensitivity of the model to parameter changes over a broad range of plausible values is used to analyze the nonlinear aspects of the model. The end result is a deeper insight into the conditions under which the process change will succeed and improved recommendations for process change design and implementation.

A group of engineers at MITRE collaborated and are emphasizing how the performance engineering (PE) practice assures systems meet their operational performance goals. To that end, MITRE engineers have developed a number of PE tools, such as the Modeling Environment for SOA Analysis (MESA). MESA (developed in Extend) provides end-to-end modeling and simulation environments for studying service-oriented architectures (SOA).

Computer Simulation Modeling for Recreation Management: A Study on Carriage Road Use in Acadia National Park, Maine, USA details the use of computer simulation as a tool for describing visitor travel on the carriage roads of Acadia National Park, Maine, USA. The findings of this study suggest that computer simulation is useful for estimating current carrying capacity conditions, predicting future conditions, and guiding related research.

An energetic materials environmental study was completed with participation from NASA, the Environmental Protection Agency, and others to define the environmental impact of energetic materials. The Extend model developed for this project helped to identify eleven areas for which The Strategic Environmental Research and Development Program (SERDP) might consider promoting future research and development work, plus the model calculated the propellant cost for each manufacturing activity.

Developed in Extend, the LIFE (Low Impact Feasibility Evaluation) model establishes functional connections between different land uses and landscape features. It can be used for:

	Design of volume or water quality based stormwater controls.
	Review of development/re-development plans for compliance with stormwater regulations.
	Incentive-based approaches such as environmental credit trading.
	Public education and outreach.

Using Extend, the authors constructed a system model, MOSIM, that uses the physical reservoir data and minimum releases for hydropower and environmental constraints from a long-term study of the Missouri River basin. The value was based on the hydropower generated by the main-stem dams for a simulated period of 1898–1996 using MOSIM. Simulated forecasted flows were generated to represent the levels of predictability that had been determined in a previous study. The results demonstrate that use of climate forecast information along with better definition of the basin moisture states can improve runoff predictions with modest economic value that, in general, will increase as the size of the reservoir system decreases.

In collaboration with a major utility facing major storms on an annual basis, Davies Consulting Inc. developed an innovative simulation model that allows decision makers to evaluate the affect of strategic decisions on storm restoration prior to and after a storm has struck.

Designing a new biological facility or planning the expansion of an existing one requires evaluation of several parameters related to product characteristics, equipment capability, and facility capacity. Decisions made at the design stages are critical to the validation plan and the ongoing operation if it is a commercial facility. Whether the facility will provide the needed future capacity is one of the critical questions requiring a credible answer. This article describes a methodology that uses Extend simulation software as a capacity planning and design tool.

The Westinghouse Savannah River Company successfully created an Extend model that assessed material throughput and validated the equipment list for the conceptual design of a manufacturing facility. Generic powerful autonomous blocks were developed that can automatically read and write to multiple tables; automatically adjust the manufacturing process based upon the characteristics of the item received; and can be rapidly reconfigured to investigate alternate process characteristics, changes in the number, type, and or location of the workstations; and the characteristics of the transport system. Preliminary calculations were completed that favorably compare with the original throughput model.

Any activity that receives inputs and convert them to outputs can be considered a process. So, essentially, similar equations are used in the theory of chemical, biochemical, nuclear, mechanical, and other types of process engineering modeling. This particular research group set out identify the processes, network of processes, process variables and process equations in food logistics. This paper introduces how process building, simulation run, and optimization can be carried out in a Food Distribution Centre with a message-based discrete event simulation software (ExtendSim). Simulation usage as a decision supporting tool in the hand of company management is introduced as well as the affect of wrong decisions on the extent of air pollution coming out from cooling vehicle.

The supply chain for fresh produce consists of many links: producer/grower, warehouse, packing center, distribution center, retailers, and finally the consumer. Each of these is a system in itself, interacting with the other components of the supply chain.

Due to requirements of produce storage, the processing plant, and saving in the
traceability process, often small size lots are merged together to form a large size lot at some point in the supply chain. This larger lot size could imply higher risk for the consumers in case of recall of the produce and much higher recall time and cost for the supply chain.

When a non-conformity occurs, the time to recall the produce depends on many factors: lot size, lead time for information spreading from link to link, product transit time among links, product storage procedures and times, and the point in the supply chain where the problem occurred. Using ExtendSim, the authors built a model to study different scenarios for a recall procedure.

Packages that accurately emulate the hybrid processes that characterize food and beverage manufacturing are making simulation more than just a snazzy presentation tool for upper management. Users are roughing out their production and packaging lines on screen to gain insight into the dynamics of their lines and where and why bottlenecks occur.

Project undertaken by the Department of Energy Strategic Petroleum Reserve (SPR) to reengineer its supply chain to reduce expenses, decrease need-fulfillment time, and improve the storage and dissemination of information.

The Leeds & Wakefield Breast Screening Service & Primary Care Trusts asked Focused_On Limited to build a Demand & Capacity simulation model focused on the number of Mobile and Static Screening facilities and the Screening Staff needed to cope with background population increases and the Age Extension Strategy.

Results of their ExtendSim model and report, "...saved buying at least 2 new Screening machines and Leeds & Wakefield now has a blue-print for success."

Studies of memory T cell differentiation tend to be hampered by a lack of quantitative models to test hypotheses in silico before in vivo experimentation. Using Extend, researchers from the Nephrology Unit and Department of Surgery at the University of Rochester Medical Center in Rochester, New York built a model of CD4+ memory T cell generation capable of tracking individual lymphocytes.

Explores the potential of discrete event simulation (DES) methods to advance system-level investigation of emergency department (ED) operations. To this end, the authors describe the development and operation of Emergency Department SIMulation (EDSIM), a new platform for computer simulation of ED activity at a Level 1 trauma center. The authors also demonstrate one potential application of EDSIM by using simulated ED activity to compare two patient triage methods.

This paper describes the construction of a computer model that simulates the hypothalamic-pituitary-adrenal axis (HPA axis) regulation of cortisol production.

Working with the South Tyneside Primary Care Trust, Focused_On Health Limited used Extend to help redesign processes to improve patient access to psychological therapies, deliver greater care, and provide a better value for the money.

The U.S. Army uses Combat Support Hospitals (CSHs)—mobile, deployable hospitals housed in tents and expandable containers—to provide surgical and trauma care close to combat action.A CSH is a 248-bed hospital staffed by approximately 500 personnel. Modular in design, it can also operate as two geographically separated hospitals ("split-based operations"), one with 164 beds and the other with 84 beds. CSHs provide the highest level of in-theater medical care available to American military personnel serving in active, deployed operations, including stabilization and surgical capabilities comparable to those in the trauma centers of major hospitals in the United States. Currently the Army has 29 CSHs, soon to be reduced to 26: 10 in the active component (8 in the continental United States and 2 forward stationed in South Korea and Germany) and 16 in the U.S. Army Reserve.

Krannert professors Suresh Chand (left) and Herb Moskowitz (right) are leading a project team that uses management principles to increase the efficiency of healthcare delivery. What began as an MBA class project at Purdue University’s Krannert School of Management is now applying factory management techniques to a medical clinic, ultimately improving productivity and quality. The student-faculty team’s approach to improving healthcare clinic operations is, of necessity, “multipronged.” Ultimately, the research applies the principles of engineering, management, science, and information technology to improve the delivery of healthcare to consumers.

A large hospital in southeast United States utilized simulation to aid project leaders in advancing to the next level of sophistication with Six Sigma. The project produced an ongoing, workable model from which potential process improvements in their Emergency Department (ED) were simulated. Project leaders tested several scenarios in the ED Simulation to quantify their value proposition. The simulation model also enabled the hospital to test design ideas of a planned new facility.

This case study demonstrates the value of simulation modeling in the healthcare architecture design of a new ambulatory surgery unit. The simulation developed explores the relationship between the number of operating rooms and recovery beds, the number of cases and the phases of recovery, bed capacity, staffing, and waiting room seat requirements as each affected the design. Model results allowed time for variations in the design to meet the client's needs before the project was built. Furthermore, the simulation shows the positive outcome of combining the experience of three professional disciplines: healthcare planning, architecture, and simulation modeling for nurses, doctors and patients of the new ambulatory surgery unit.

Simulation modeling is a tool of hospital-wide system process change with a focus on improving patient satisfaction through a better clinical process. Some of the improvements, based on existing systems, include decreased delays, better healthcare staff utilization and tailored scheduling. In this part 2 of 2 perioperative case studies (part 1: Ambulatory Surgery Unit), the experiences of three distinct, yet complimentary professions are combined and opitimized: nursing/healthcare planning, architecture, and simulation engineering to create a better way to provide a clinical service in a newly designed healthcare space. Complete paper to be posted soon.

Pilot experience in the adoption of performance simulation approach to design, redesign, and acquisition of bottling lines. Discusses the management of huge bottling resources of a company: more than 36 lines in 12 factories, in 6 countries, with an aggregated investment value of $ 200 million, occupying more than a thousand people and producing 250 million cases a year of 300 different SKUs.

Simulation of a wafer fabrication line to assist in the meeting of delivery schedules, reducing product cycle times, increasing product yield and throughput, optimizing equipment utilization, and increasing confidence for on-time delivery and profits.

Inventory management of multi-echelon repairable item structures have been largely studied. Restrictions on its applications to real case problems were difficult to overcome. To surpass some of these limitations, the authors used ExtendSim to create a simulation model that not only examines a multi-echelon structure system, but also permits the explicit consideration of a hierarchical structure for repairable and consumable items. Model results balance inventory policy which guarantees a certain level of service accounting for operations occurrence and repairs conditions.

An ExtendSim model of a two-level inventory control system for a homogenous product is examined in this report. The model includes stocks showing both the wholesaler's and customers' warehouses, each characterized by a random demand for product and random time of product delivery.

The completed model could be used for examining dynamics of the stocks' level at the warehouses of the customers and the wholesaler. It could also be used to search for an optimal decision for a company having its own wholesale warehouse and a network of its own enterprises-customers. The future plan is investigation of different variants of wholesaler's ordering policy.

Learn more about the inventory control system here.

This paper compares the use of a spreadsheet vs. ExtendSim to create Monte Carlo simulations to manage inventory and design a supply chain. Models created were optimized to find the minimal inventory cost.

Brief introductory article discussing the key element in lean implementation: simulation.

Working as a team, Crutchfield Corporation, a major consumer electronics catalog and Internet retailer, and Rust Management Technology used Extend and ExpertFit to develop and validate a distribution center process simulation using Six Sigma techniques. Using insights developed through the simulation, Crutchfield Corporation estimates that it will save 15 to 20 times the cost of the project in the first year after deployment. Paper is currently not available online.

This paper presents a case study where simulation was used to convert from a manufacturing resource planning (MRP) based push process to a demand-driven pull process in a single plant operation factory floor.

Lean Simulation Models introduces the use of simulation models as essential tools for lean programs to test alternative solutions before implementing them. Mr. Curry highlights benefits of using Extend and includes screenshots of numerous sample models.

A large hospital in southeast United States utilized simulation to aid project leaders in advancing to the next level of sophistication with Six Sigma. The project produced an ongoing, workable model from which potential process improvements in their Emergency Department (ED) were simulated. Project leaders tested several scenarios in the ED Simulation to quantify their value proposition. The simulation model also enabled the hospital to test design ideas of a planned new facility.

Simulation Modeling in Lean Programs is a good overview paper on the use of Extend in lean manufacturing. Defines simulation and highlights a few areas where it can be most valuable.

As part of its process excellence program, in 2005, Johnson & Johnson commissioned the building of a simulation model to examine current operations and develop solutions for the future for one of its large pharmaceutical plants. This paper describes how simulation evolved from improvement and capacity projects to the ongoing planning and management process.

The tool developed by ExtendSim Consultant The OpStat Group, was not intended to be a one-time project, but rather a short/mid/long term capacity planning and continuous improvement tool. Since the model's inception, as in most facilites, options were continually being considered for the suppply chain network.The work stream mirrored by the ExtendSim model is one, if not the largest for this technology in the J&J network and is usually key to any network decisions. It has become central to plant management decision-making.

Ultimately, significant benefits in delivering positive change at Johnson & Johnson ensued, including:

	Better utilization of personnel by not squandering their time on projects that would not deliver expected results. Without adding staff, J&J was working smarter by using the tool to pre-test process change.
	Accelerated delivery of value-added projects that improved cycle time, throughput, and inventory by assisting in the selection of lean techiques and parameters to achieve optimum solutions across combined upstream and downstream operations.
	Improved accuracy and timeliness of planning information for plant and supply chain management to evaluate options for sourcing and capacity within the plant and across the supply chain.

Cognitive Process Simulation in Wine Making: Determining the Best Route for Wine Transfers describes the use of simulation to create a cognitive model of the actions of certain winery workers.

This report is a user's guide for the Engine Maintenance Systems Evaluation (EnMasse). EnMasse is a simulation model built in ExtendSim and used in the analysis of alternative Jet Engine Intermediate Maintenance (JEIM) policies.

The result of the policy analysis conducted using EnMasse is reported in a companion document, Supporting Expeditionary Aerospace Forces: Alternatives for Jet Engine Intermediate Maintenance, MR-1431-AF, 2002, ISBN 978-0833031037. The goal of this analysis was to evaluate several alternatives for
accomplishing JEIM support. Closely allied to maintenance policy are the maintenance structures within which these policiesoperate both in peace and war.

Click here to view the EnMasse report.

The Guardian Installation Protection Program (IPP), a program within the Joint Program Executive Office for Chemical and Biological Defense to protect 200 military installations world-wide from chemical, biological, and radiological threats, developed and accredited the IPP System Effectiveness Model. This model helps evaluate installation designs and make programmatic decisions. It assists a product manager to make a myriad of acquisition and design decisions and measure the performance of a design before it is fielded. By catching key design flaws before they are fielded, analysis can be performed to help define alternative operational procedures and new design requirements early in the acquisition process and avoid fielding delays and unexpected costs. This innovative toolset is the first of its kind that has the ability to effectively model complex military environments, multiple threats, and innovative designs that combine materiel and non-materiel components into one Family of Systems.

Boeing and the Naval Postgraduate School (NPS) developed an Extend model of an organizational concept called Standing Joint Forces HQ (SJFHQ) being developed at the U.S. Joint Forces Command (JFCOM). The modeling objective was to measure personnel utilization and organizational process efficiency. Here is the NPS final report and an abbreviated presentation given at a public command and control conference. The final report contains a lot of information about the actual Extend model developed.

Presentation

Final Report

Cognitive Process Simulation in Wine Making: Determining the Best Route for Wine Transfers describes the use of simulation to create a cognitive model of the actions of certain winery workers.

Brief introductory article discussing the key element in lean implementation: simulation.

Due to the complexity and diversity with which wines are produced, there's an incredible need to track the numerous variables for this process. Plus, strict state laws regarding the production and sale of alcohol requires vintners to trace everything from the sugar content of the grapes right down to the heritage of the grapes that contribute to each bottle of wine. This article summarizes the wine industry's adoption of IT in a number of creative ways, including its use of simulation.

Working as a team, Crutchfield Corporation, a major consumer electronics catalog and Internet retailer, and Rust Management Technology used Extend and ExpertFit to develop and validate a distribution center process simulation using Six Sigma techniques. Using insights developed through the simulation, Crutchfield Corporation estimates that it will save 15 to 20 times the cost of the project in the first year after deployment. Paper is currently not available online.

This paper presents a case study where simulation was used to convert from a manufacturing resource planning (MRP) based push process to a demand-driven pull process in a single plant operation factory floor.

LED (Light Emitting Diode) has many excellent features as a new lighting device and is now widely used. This paper introduces the structure and light-emitting principle of LED and explains the LED manufacturing process, dynamically showing it with FLASH CS. An LED processing line is modeled and simulated through the dynamic software ExtendSim. The simulation result is analyzed and processing line balanced. Ultimately, throughput is improved with simulation.

Access paper

 

This paper describes the logic and assumptions used in building a simulation model of an Automated Material Handling System (AMHS) for an eight inch Wafer FAB. The model includes the ability to make changes to the area stocker layout, number of area stockers, number of loops, number of cars, and/or the number of Lot moves. This model is used to determine if the Area Stockers can handle the quantities of Lots per hour required by From-To-Table "customer" requirements.

In Simulation's Strength, Extend helped a print publisher save hundreds of thousands of dollars by pointing out the optimal amount of equipment needed for a large-scale publishing operation.

Packages that accurately emulate the hybrid processes that characterize food and beverage manufacturing are making simulation more than just a snazzy presentation tool for upper management. Virtual Engineering's New Frontier describes users roughing out their production and packaging lines on screen to gain insight into the dynamics of their lines and where and why bottlenecks occur.

In a 3-year project funded by FCS Research through United States Military Academy, Innovative Decisions, Inc. created a Dynamic Decision Network (DDN) utilizing ExtendSim in conjunction with other software tools. The DDN created is a combination of an influence diagram and a Bayesian network that addresses specific problems.

This report is a user's guide for the Engine Maintenance Systems Evaluation (EnMasse). EnMasse is a simulation model built in ExtendSim and used in the analysis of alternative Jet Engine Intermediate Maintenance (JEIM) policies.

The result of the policy analysis conducted using EnMasse is reported in a companion document, Supporting Expeditionary Aerospace Forces: Alternatives for Jet Engine Intermediate Maintenance, MR-1431-AF, 2002, ISBN 978-0833031037. The goal of this analysis was to evaluate several alternatives for
accomplishing JEIM support.Closely allied to maintenance policy are the maintenance structures within which these policiesoperate both in peace and war.

Click here for the EnMasse report.

By assuming existing structure from 1st and 2nd Force Reconnaissance Companies, MARSOC was able to initiate operational deployments of company-sized elements a little more than one year after establishment of the Command.  In addition, deployments by the Foreign Military Training Unit (FMTU), re-designated as the Marine Special Operations Advisory Group (MSOAG) have continued and are increasing in terms of locations, duration and frequency. 

While supporting an expanding range of deployments and establishing the structure to recruit, screen, assess, select and train operators, MARSOC has also confronted the challenge of developing an appropriately sized logistic capability.  In the near term, this capability must support deployments of 14 to 54 operators, ranging from six weeks to six months, while respecting a 1:2 dwell time.  While the Special Operations Forces Support Activity (SOFSA) provides complete support to all SOF-specific equipment, the Marine Corps must support the forces and equipment it provides to SOCCOM.

Go to Final Report Wiki
Download Final Report
Download ExtendSim model files

In less than two years, MARSOC will reach Fully Mission Capable (FMC) status. At that point, the Command must be able to support deployments of battalion-sized elements, organized to function as Joint Special Operations Task Force Headquarters (JSOTF HQ). 

During the transition period from IOC to FOC, much of the operational effort will be focused on support to CENTCOM in OIF and OEF.  After 2010, the proportion of deployments to austere theaters will increase; significantly increasing the demands on the Command’s organic logistics capability.

The Indian Head Division Naval Surface Warfare Center (IHD/NSWC) contracted the National Defense Center for Environmental Excellence (NDCEE) to develop a process and environmental cost-analysis simulation for gun propellant processing. Using Extend, they built a model specific to the extrusion of both solvent and solventless thermoplastic elastomer (TPE) propellants. This model accurately predicts the cost impacts of alternative processes before implementation can be initiated.

The Guardian Installation Protection Program (IPP), a program within the Joint Program Executive Office for Chemical and Biological Defense to protect 200 military installations world-wide from chemical, biological, and radiological threats, developed and accredited the IPP System Effectiveness Model. This model helps evaluate installation designs and make programmatic decisions. It assists a product manager to make a myriad of acquisition and design decisions and measure the performance of a design before it is fielded. By catching key design flaws before they are fielded, analysis can be performed to help define alternative operational procedures and new design requirements early in the acquisition process and avoid fielding delays and unexpected costs. This innovative toolset is the first of its kind that has the ability to effectively model complex military environments, multiple threats, and innovative designs that combine materiel and non-materiel components into one Family of Systems.

Boeing and the Naval Postgraduate School (NPS) developed an Extend model of an organizational concept called Standing Joint Forces HQ (SJFHQ) being developed at the U.S. Joint Forces Command (JFCOM). The modeling objective was to measure personnel utilization and organizational process efficiency. Here is the NPS final report and an abbreviated presentation given at a public command and control conference. The final report contains a lot of information about the actual Extend model developed.

Presentation

Final Report

The U.S. Army uses Combat Support Hospitals (CSHs)—mobile, deployable hospitals housed in tents and expandable containers—to provide surgical and trauma care close to combat action.A CSH is a 248-bed hospital staffed by approximately 500 personnel. Modular in design, it can also operate as two geographically separated hospitals ("split-based operations"), one with 164 beds and the other with 84 beds. CSHs provide the highest level of in-theater medical care available to American military personnel serving in active, deployed operations, including stabilization and surgical capabilities comparable to those in the trauma centers of major hospitals in the United States. Currently the Army has 29 CSHs, soon to be reduced to 26: 10 in the active component (8 in the continental United States and 2 forward stationed in South Korea and Germany) and 16 in the U.S. Army Reserve.

"Extend is one of the most powerful and sophisticated software programs I have worked with in a long time." reports Dale Farris, VP of the Golden Triangle PC Club. In this thorough review of Extend 6, Mr. Farris highlights some of the features and advantages of using Extend.

Dean of engineering, technology, and computer science at Indiana University-Purdue University offers his point of view on Extend.

This report shows how process simulation modeling (PSIM) can help companies improve processes and achieve higher levels of process maturity and capability as called for by the Capability Maturity Model® Integration (CMMI®)1 [SEI 2006]. CMMI was developed by a team consisting of members from industry, government, and the Software Engineering Institute (SEI).This report is aimed at practitioners, especially software development project managers, and researchers studying software development processes. The report describes a variety of PSIM applications and discusses how PSIM has helped organizations to improve their implementations of CMMI areas toward higher levels of process capability, maturity and performance.

Optimization of Simulated System Effectiveness Using Evolutionary Algorithms is a brief discussion of the use of evolutionary algorithms in system optimization.

General introductory article on terms used in simulation and the benefits of using simulation.

In this review of Extend 4 written in 1999, the author highlights numerous Extend features which facilitate model building. The pricing, system requirements for Extend, and package names are outdated, but most of the remainder of his review is still valid (with the exception of features added in later versions of ExtendSim and Extend which merely add to its appeal).

Eleven Critical Pitfalls in Simulation Modeling is a synopsis of some of the ideas presented in Averill Law's three-day simulation short courses.

This paper compares the use of a spreadsheet vs. ExtendSim to create Monte Carlo simulations to manage inventory and design a supply chain. Models created were optimized to find the minimal inventory cost.

The United States Air Force, in accordance with the Department of Defense's mission to modernize its processes, systems, and information flows, began an effort to replace legacy systems with two Enterprise Resource Planning (ERP) systems (USDoD, 2007a). Nova Technology Solutions (NovaTech), an Information Technology (IT) and Analytics firm, recognized the Air Force's need for a repeatable, reliable, tool to aid decisionmaking during the planning, installation, and sustainment of these ERP systems, thus proposing the use of modeling and simulation. ExtendSim was used to create a simple simulation model to analyze the impact of ERP increased workload on network performance, specifically at the Air Force Service Delivery Points (SDPs).

Results from the NovaTech model show that a 15% increase in current workload, or current network traffic, will cause a 250% increase in end-user response time (Fitzgerald & Harper, 2008), while the model used for Ms. Harper's thesis showed a 98%, 209%, and 352% increase in response time when the current workload is increased by 10%, 20%, and 30%, respectively. In an experiment investigating the impact of capacity expansion in the model with the double resource SDP, it was determined that for a 30% increased workload a 42.5% increase in SDP bandwidth capacity at the base hosting the application server resulted in a 75% decrease in average end-user response time during the peak traffic hour.

Tiffany Jill Harper
A thesis submitted in partial fulfillment of the requirements for the degree of
Master of Science in Engineering, Wright State University, 2008

Variability in production is one of the largest factors that negatively impacts construction project performance. A common construction practice to protect production systems from variability is the use of buffers (Bf). Construction practitioners and researchers have proposed buffering approaches for different production situations, but these approaches have faced practical limitations in their application.

In Multiobjective Design of Work-In-Process Buffer for Scheduling Repetitive Building Projects, a multiobjective analytic model (MAM) is proposed to develop a graphical solution for the design of Work-In-Process (WIP) Bf in order to overcome these practical limitations to Bf application, being demonstrated through the scheduling of repetitive building projects. Multiobjective analytic modeling is based on Simulation–Optimization (SO) modeling and Pareto Fronts concepts. Simulation–Optimization framework uses Evolutionary Strategies (ES) as the optimization search approach, which allows for the design of optimum WIP Bf sizes by optimizing different project objectives (e.g., project cost, time and productivity). The framework is tested and validated on two repetitive building projects. The SO framework is then generalized through Pareto Front concepts, allowing for the development of the MAM as nomographs for practical use. The application advantages of the MAM are shown through a project scheduling example. Results demonstrate project performance improvements and a more efficient and practical design of WIP Bf. Additionally, production strategies based on WIP Bf and lean production principles in construction are discussed.

Note: This paper was made possible with the help of an ExtendSim Research Grant for the final project of Vicente González in obtaining his PhD in Construction Management from Pontificia Universidad de Católica de Chile.

	Download final report (664 KB): "Work-In-Process Buffer Design Methodology for Scheduling Repetitive Building Projects" by Vicente González and Luis F. Alarcón
	Download Extend OR 6 model files (5.7 MB). You may view these models in ExtendSim or download the ExtendSim Demo.

Optimization of Simulated System Effectiveness Using Evolutionary Algorithms is a brief discussion of the use of evolutionary algorithms in system optimization.

Pilot experience in the adoption of performance simulation approach to design, redesign, and acquisition of bottling lines. Discusses the management of huge bottling resources of a company: more than 36 lines in 12 factories, in 6 countries, with an aggregated investment value of $ 200 million, occupying more than a thousand people and producing 250 million cases a year of 300 different SKUs.

This paper describes the use of simulation as a tool to analyze the baggage handling system at the airport of Riga, Latvia. The ExtendSim model created for this study examines the effect of increasing passenger flow on the future staffing and equipment needs of the existing baggage handling system.

Consider a single-server queue with a renewal arrival process and generally distributed processing times in which each customer independently reneges if service has not begun within a generally distributed amount of time. A Diffusion Approximation for a GI/GI/1 Queue with Balking or Reneging establishs that both the workload and queue-length processes in this system can be approximated by a regulated Ornstein-Uhlenbeck (ROU) process when the arrival rate is close to the processing rate and reneging times are large. This paper further shows that a ROU process also approximates the queue-length process, under the same parameter assumptions, in a balking model. This balking model assumes the queue-length is observable to arriving customers, and that each customer balks if his or her conditional expected waiting time is too large.

The authors created a prototype simulation model of the dynamics of defect evolution (introduction, detection, and removal) and of the process factors that influence it throughout the entire development lifecycle of a software product. The simulation model presented is a tool that supports reliability prediction as well as cost and schedule estimation. It helps the user to forecast the impact of different reliability practices not only on software reliability (effectiveness), but also on cost and development time (efficiency). This article describes the model created and presents a hypothetical example illustrating how an organization could use the simulation tool to make decisions regarding reliability strategies.

PowerPoint presentation of a decision support tool used for long-term, rough-cut resource and capacity planning. IRPM evaluates the impact of rapidly changing schedules, variable budgets, and changing resource bases (i.e., personnel, equipment, and facilities and their effects on schedule performance, projected cost, and resource utilization).

This research was subsidized by an ExtendSim Research Grant

Radio frequency identification (RFID) technology has significant impact on product tracking and identification in manufacturing systems. Most of the business cases that implement the RFID technology in their operations have achieved various benefits. RFID technology can reduce the operating errors that affect the efficiency of the operations which results in improving different performance measures such as cycle time, throughput, work-in-process, resources utilization, and average waiting time in queues. In addition, several benefits such as improved items monitoring, lower lead times, and better inventory control can be achieved by introducing RFID technology. Recent developments in RFID technology and other supporting technologies have created opportunities for real-time traceability and better visibility in
shop floor operations.

This paper investigates the effectiveness of introducing RFID technology in tracking and identification processes for products flow in a job shop manufacturing facility. A leading furniture manufacturer in Egypt has been selected as a case study. The manufacturer produces a large number of customized furniture products. Errors in tracking and identification usually occur due to the large number of products present on the shop floor. Introduction of radio frequency identification technology at different stages of manufacturing is proposed to overcome these errors. Different simulation models have been developed for the post-assembly processes in the facility. These models have been developed with an intent to capture all the features that characterize a real furniture manufacturing facility. Simulation is used to assess the impact of introducing the RFID technology on a number of performance measures. Analysis and comparison of simulation results for the base and proposed models show that RFID implementation can improve the overall performance of the facility.

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Download model files (created in ExtendSim 7 so can be viewed in either 7 or 8)

 

OR/MS Today is a publication provided as a benefit to INFORMS members. Along with a few other simulation tools, the article "When Close is Better Than Optimal" featured in the December 2010 issue of OR/MS Today mentions ExtendSim as a valuable tool simulation tool.

An excerpt from the article:

"This brings us to ExtendSim, formerly called just Extend, which this reporter regards as the closest to the overal capability at this time. ExtendSim has the ease of learning and use and the robust user base to stay in this market, good animation features, and full integration with data input, via spreadsheets or from some database packages, and fitting probability distribution to these inpt data asets. The latest version also includes a Scenario Manager that tracks changes in inputs and associated output files. It creates a record of runs and results and thereby supports a general experimental management activity. This also facilitates communication with more advanced, full-featured experimental design routines...."

Click here to become an INFORMS member and read the remainder of the article.

Explores the potential of discrete event simulation (DES) methods to advance system-level investigation of emergency department (ED) operations. To this end, the authors describe the development and operation of Emergency Department SIMulation (EDSIM), a new platform for computer simulation of ED activity at a Level 1 trauma center. The authors also demonstrate one potential application of EDSIM by using simulated ED activity to compare two patient triage methods.

The authors created a prototype simulation model of the dynamics of defect evolution (introduction, detection, and removal) and of the process factors that influence it throughout the entire development lifecycle of a software product. The simulation model presented is a tool that supports reliability prediction as well as cost and schedule estimation. It helps the user to forecast the impact of different reliability practices not only on software reliability (effectiveness), but also on cost and development time (efficiency). This article describes the model created and presents a hypothetical example illustrating how an organization could use the simulation tool to make decisions regarding reliability strategies.

This paper illustrates the use of discrete event stochastic simulation modeling to compare two scheduling (dispatching) policies, first-in-first-out (FIFO), and Minimum Inventory Variability Policies (MIVP), for machines in a factory. The model developed observes and compares machine utilization, records queue statistics, plots mean cycle time and mean WIP, calculates production throughput, can push bottleneck capacity to it’s limit, test setup rules and machine controllers, try preventive maintenance schedules, and determine personnel (operator) requirements.

This report documents a computer-based simulation of Unemployment Insurance(UI) benefit processing developed by the Unemployment Insurance (UI) Information Technology Support Center (ITSC) under its Benefit System Modernization project. The Extend model created for this project can be used to investigate and evaluate various steps in processing UI initial claims and customized for each state's individual requirements. This report describes the basic structure of the computer-based simulation, its operation, including methods to vary the input parameters, methods to view the results of simulation, and instructions on obtaining a free copy of the benefit processing model.

Simulation models are typically built to obtain an understanding of the system dynamics and compare alternatives. ExtendSim’s Scenario Manager provides an easy interface to evaluate different model configurations and explore the effects of model parameters. Scenario management provides for a systematic, controlled approach to the investigation of a system or process. Among other things, it can be used for problem solving ("what are the main factors contributing to the problem"), parameter design ("how well does the system/process perform given specified factors"), and robustness studies (what is the best configuration of factor values to maximize/minimize variations in response".) Thus it has a very broad application across all disciplines.

Each month, Simulation magazine features a different simulation application on its cover. In August 2000, a model of an airport security checkpoint was chosen. This model utilized Extend bundled with Proof Animation (Extend Suite) to simulate and animate proposed changes to an existing security system. For more details on the model, click here or on the cover.

Letter by letter, the authors summarize 26 of what they consider to be important components for applying knowledge and judgment to simulation problems. They do not claim that these are “the” 26 components. Other simulation analysts could have another set, or they could have multiple components for one letter of the alphabet.

This report shows how process simulation modeling (PSIM) can help companies improve processes and achieve higher levels of process maturity and capability as called for by the Capability Maturity Model® Integration (CMMI®)1 [SEI 2006]. CMMI was developed by a team consisting of members
from industry, government, and the Software Engineering Institute (SEI).This report is aimed at practitioners, especially software development project managers, and researchers studying software development processes. The report describes a variety of PSIM applications and discusses how PSIM has helped organizations to improve their implementations of CMMI areas toward higher levels of process capability, maturity and performance.

Success in your first simulation model is crucial for the overall prospects of a new simulation program. This paper outlines the building of your first simulation model with emphasis on the overall process and what it takes to be a successful model builder.

Competition from China can be daunting. How can high-tech manufacturers in the US compete with the lower product cost from manufacturers in China?

In this article, Mr. McQuarrie uses ExtendSim to model a high-density complex fab plant to determine how much money the plant can make. From there, results are analyzed to better understand operations and work collaboratively tomastermind how to produce with higher yields and run product.

The video further describes the modeling process in ExtendSim.

In the August issue of The PCB Magazine, Gray MacQuarrie, president of Grayrock & Associates, uses ExtendSim to illustrate that "as you improve your scrap rate you can reduce the delivery time on quick-turn lots, which may allow you to earn a higher performance premium." Learn more.

Dynamic Simulator for WIP Analysis in Semiconductor Manufacturing describes the implementation of a FAB Simulator and Capacity Planner in a semiconductor FAB in Arizona that assists the operational planner with the planning of the daily production mix. This paper was presented to top semiconductor firms from all over the world at the International Symposium Semiconductor Manufacturing conference.

Simulation of a wafer fabrication line to assist in the meeting of delivery schedules, reducing product cycle times, increasing product yield and throughput, optimizing equipment utilization, and increasing confidence for on-time delivery and profits.

This paper illustrates the use of discrete event stochastic simulation modeling to compare two scheduling (dispatching) policies, first-in-first-out (FIFO), and Minimum Inventory Variability Policies (MIVP), for machines in a factory. The model developed observes and compares machine utilization, records queue statistics, plots mean cycle time and mean WIP, calculates production throughput, can push bottleneck capacity to it’s limit, test setup rules and machine controllers, try preventive maintenance schedules, and determine personnel (operator) requirements.

Simulation study conducted by a Fortune 100 semiconductor manufacturer to modify their operations.

This paper describes the logic and assumptions used in building a simulation model of an Automated Material Handling System (AMHS) for an eight inch Wafer FAB. The model includes the ability to make changes to the area stocker layout, number of area stockers, number of loops, number of cars, and/or the number of Lot moves. This model is used to determine if the Area Stockers can handle the quantities of Lots per hour required by From-To-Table "customer" requirements.

This research was subsidized by an ExtendSim Adopter University

"Wafer lot release policies based on the continuous and periodic review of WIP levels" evaluates the impact of different lot release policies on the performance of semiconductor wafer fabrication facilities (wafer fabs). Lot release policies presented in this work are based on continuous review and periodic review inventory control policies. Proposed policies can be considered as modifications to the well known CONstant Work-In-Process (CONWIP) method. Simulation of the Intel Mini-Fab model is used to compare the performance of the fab using the CONWIP method to using these proposed policies. Additionally, two different dispatching rules are used at the bottleneck station to evaluate its impact on the fab performance when combined with the release policies. Performance is measured using an overall efficiency measure to represent the changes that occur in both cycle time and throughput rate. The work shows that periodic WIP review can improve the performance of the fab; while, continuous WIP review will have the same effect of the CONWIP method.

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Many service providers offer customers the choice of either waiting in a line, or going offine and returning at a dynamically determined future time. The best known example is the FASTPASS® system at Disneyland. To operate such a system, the service provider must first make an upfront decision on how to allocate service capacity between the two lines. Then, during system operation, he must dynamically provide estimates of the waiting times at both lines to each arriving customer. The estimation of offine waiting times is complicated by the fact that some offine customers do not return for service at their appointed time.

The paper Managing Service Systems with an Offine Waiting Option and Customer Abandonment shows that when demand is large and service is fast, for any fixed capacity allocation decision, the two-dimensional process tracking the number of customers waiting inline and offine collapses to one dimension, and characterize the one-dimensional limit process as a reflected diffusion with linear drift.

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The analytic tractability of this one-dimensional limit process allows to solve for the capacity allocation that minimizes average cost, when there are costs associated with customer abandonments and queueing. It is further shown that in this limit regime, a simple scheme based on Little's law to dynamically estimate inline and
offline wait times is effective.

Note: This paper was made possible with the help of an ExtendSim Research Grant for the final project of Vasiliki Kostami in obtaining his PhD in Operations Management from the University of Southern California.

Project undertaken by the Department of Energy Strategic Petroleum Reserve (SPR) to reengineer its supply chain to reduce expenses, decrease need-fulfillment time, and improve the storage and dissemination of information.

Does it really make sense to roll
the dice with an important customer order, just because of the inherent unreliability of your metal finishing operation? If so, it may be time for you to change the game—today.

In the October 2012 issue of The PCB Magazine, Gray MacQuarrie, president of Grayrock & Associates, introduces an ExtendSim model that could be used to illustrate cost to a business when a worst-case scenario happens and how you could best handle the situation with your customer. Learn more.

How we manage our scrap events
determines whether our business thrives or dies. Consider a policy to start absolute-lot quantities,
which means, no extras, ever.

In the October 2012 issue of The PCB Magazine, Gray MacQuarrie, president of Grayrock & Associates, uses ExtendSim to illustrate the option of restarting jobs
in which you start absolute-lot quantities—no extras—even though this requires disciplined execution and a tightly timed and reliable production
process. This option could make your operation extremely profitable—if you can do it. Learn more.

Biofuels are transport fuels made from organic material. The most common biofuels today are biodiesel (made from vegetable oils) and bioethanol (made from sugar and starch crops). Research is under way to commercialize “second-generation” production techniques that can make biofuels from woody material, grasses, and some additional types of waste. Biofuels have a unique role to play in European energy policy. They are today the only direct substitute for oil in transport that is available on a significant scale.

This paper that was originally presented at the 7th International Scientific Conference on Engineering for Rural Development in May of 2008 in Jelgava, Latvia. It provides a short overview of the strategies and action plans in production and use of biofuels in Europe and Latvia. Then, existing solutions in the
improvement of biofuel logistic systems are analyzed as well as ExtendSim as a tool for the modeling of biofuel supply chains.

Simulation study conducted by a Fortune 100 semiconductor manufacturer to modify their operations.

In Simulation's Strength, Extend helped a print publisher save hundreds of thousands of dollars by pointing out the optimal amount of equipment needed for a large-scale publishing operation.

This paper uses a discrete rate approach to modeling in ExtendSim simulation software for urban transport corridor simulation. Such mesoscopic traffic flow models should be understood as models where traffic flow is described in a high level of detail, but at the same time flow behaviour is presented at a low level of description.

Since the discrete rate approach is typically not used in the transport area, this paper presents the main techniques of model implementation using a discrete rate approach and the application of this approach for urban transport corridor simulation. The author concludes that development time of the
mesoscopic model is approximately 5 times less than a
development of the same microscopic model.

Learn more about the urban transport project here.

 

 

In October 2005, a North American utility sponsored a meeting of utilities to discuss the aging assets problem. Davies Consulting, Inc. (DCI) was eventually asked, on behalf of a consortium of 21 utilities, to research current methods for life cycle analysis and provide a defensible method to deal with aging asset life cycles. DCI ultimately developed a methodology to analyze historical asset failure data, created a library of predictive asset failure frequency curves, and built a web-based and analytically rigorous simulation model. Through this model, DCI has empowered utility decision makers to forecast the near and long-term financial and system performance outcomes of strategic asset replacement and maintenance decisions.

The composting process applied to the treatment of biodegradable waste materials is one of the most adequate ways to enhance the environmental performance of the municipal solid waste (MSW) management systems. In the European context where environmental policies tend to encourage solid waste minimization and recycling, home composting is an effective method to decrease the quantity of MSW to be disposed. Home composting can be used for the conversion of the organic fraction of household wastes to a stable humus-like material (the compost).

This paper presents a dynamic model that simulates the biological composting process, applied to the organic fraction of the municipal solid waste.

Results from the sCOMPOS model.

This paper describes methodologies used to perform stormwater evaluations at a Tennessee Valley Authority (TVA) facility, including hydrologic and water quality modeling. The hydrologic and water quality modeling was accomplished with the use of the LIFE™ model, developed in Extend by CH2M HILL to simulate Low Impact Development (LID). TVA is in the process of installing several demonstration projects using LID designs.

In October 2005, a North American utility sponsored a meeting of utilities to discuss the aging assets problem. Davies Consulting, Inc. (DCI) was eventually asked, on behalf of a consortium of 21 utilities, to research current methods for life cycle analysis and provide a defensible method to deal with aging asset life cycles. DCI ultimately developed a methodology to analyze historical asset failure data, created a library of predictive asset failure frequency curves, and built a web-based and analytically rigorous simulation model. Through this model, DCI has empowered utility decision makers to forecast the near and long-term financial and system performance outcomes of strategic asset replacement and maintenance decisions.

The Extend simulation environment provides the tools for all levels of modelers to efficiently create accurate, credible, and usable models. Extend’s design facilitates every phase of the simulation project, from creating, validating, and verifying the model, to the construction of a user interface which allows others to analyze the system. Simulation tool developers can use Extend’s built-in, compiled language, ModL, to create reusable modeling components. All of this is done within a single, self-contained software program that does not require external interfaces, compilers, or code generators.

Overview of Extend 6 highlighting its functionality and offering a few examples of its use.

Overview of Extend 5 highlighting some of its industry firsts, its functionality, and offering a few examples of its use.

Overview of Extend 4 highlighting its advanced features and offering a few examples of its use.

This document presents an overview of the Extend 4 modeling environment. It was presented at the Winter Simulation Conference in 1999.

Describes hierarchy and its benefits in building large discrete event models.

This document presents an overview of the Extend 4 modeling environment. It was presented at the Winter Simulation Conference in 1998.

This document presents an overview of the Extend 3 modeling environment. It was presented at the Winter Simulation Conference in 1997.