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What’s New in FlexSim

Version 2019 Update 1 (19.1)

See What’s New

Break out of 2D simulations and into a whole new world of true to life visualization. Build your models in FlexSim’s native 3D from the start – no post processing! Learn more

FlexSim includes a built-in experimenter as well as OptQuest® to allow you to maximize your system’s potential. Learn more

Drag and drop model building, intuitive controls, comprehensive help, and more combine to make FlexSim the easiest simulation software you’ll ever use. Learn more

Import your own shapes and CAD layouts, create your own objects or user libraries, customize controls, and so much more! Learn more

Discover the causes of bottlenecks and backups. Create 3D charts and graphs right in your model. Export reports and statistics. Learn more

Visualize in 3D

FlexSim was built from the ground up to give you a truly immersive 3D experience. There is no better way to see what is happening in your system than to build it in 3D.

Build in a 3D world

FlexSim was built from the ground up to take advantage of today’s advanced 3D visualizations. Drag and drop objects into a virtual world. Create spatial relationships in your model to mimic your real life system. Include custom 3D shapes and CAD layouts.

You’ll simulate not only the behavior of your real life system, but also the look and feel, allowing you to immediately see what’s going on.

Many simulation packages are built on older 2D technology – with 3D post-processors tacked on as an afterthought. Not with FlexSim. FlexSim was conceived to be the most sophisticated 3D discrete event package ever created.

View Screenshots


FlexSim uses OpenGL, the same graphics library used in today’s hottest 3D games. Realistic spatial relationships, dynamic lighting, environmental effects, and more help make your models as realistic as you like.

Immersive presentations

Build flypaths to guide your audience through the model. Add bullet points and slideswithin the model to illustrate important points along the way. Create a movie of your model to view and share.

Analyze your system

FlexSim’s powerful 3D graphics allow in-model charts and graphs to dynamically display output statistics. You can also interface with common spreadsheet and database applications to import and export data.

Statistics tracking

FlexSim automatically tracks many different datapoints including throughput, content, machine state, and utilization to name just a few.

Use FlexSim’s powerful Dashboards to create default reports or make your own custom reports to export to your favorite graphing and analysis programs.

Databases & spreadsheets

FlexSim can import data from, and export data to, all the most popular spreadsheet and database applications. Broaden your analysis by leveraging these powerful programs.


For industry leading distribution fitting, FlexSim includes ExpertFit.

Simulations require input data, usually collected in the real world. Distribution-fitting software takes your collected data and turns it into mathematical formulas that drive FlexSim’s simulations.

ExpertFit is taylored to perfectly fit your data distribution curves.

ExpertFit, a mature and feature-rich distribution-fitting power-house, determines the best-fitting probability distribution for your data in seconds.

Learn more about ExpertFit

Dr. Averill M. Law’s Simulation Courses

Experiment & optimize

Experience the predictive power of simulation with experimentation and optimization. FlexSim includes both a built-in experimenter tool as well as a fully integrated OptQuest® interface for intelligent optimization.


The experimenter allows you to quickly change mutliple sets of variables and see the results. Create scenarios by choosing which model parameters to vary. Try a handful of scenarios, or hundreds! Save time by running many replications of multiple scenarios automatically – set it up and walk away.

Running many replications allows you to obtain confidence intervals of the results. View the results of your experiments in easy to read graphs and export reports to HTML.

FlexSim's built-in experimenter allows you to run replications of multiple scenarios in order to attain confidence intervals.

FlexSim's built-in experimenter allows you to run replications of multiple scenarios in order to attain confidence intervals.

Optimize with OptQuest

Sometimes as a modeler you’re not sure which scenarios represent your system’s optimum configuration. Optquest can intelligently suggest optimized scenarios for you.

OptTek’s OptQuest optimization engine combines tabu search, scatter search, integer programming, and neural networks algorithms to efficiently identify ideal scenarios according to parameters you specify. OptQuest is fully integrated into FlexSim’s modeling interface, giving you quick access to the industry leader in intelligent optimization.
Learn more about OptQuest

Ease of use

FlexSim is designed to be user-friendly and intuitive. Sensible interfaces and straight forward usage put FlexSim at the front of simulation software usability. Plus, enjoy multiple outlets to training, help, and the most active simulation community forum on the web.

Drag & drop model building

FlexSim objects are easily customized using pre-configured picklist options to define unique behaviors.

Quickly and easily build your model by dragging objects into view and positioning them with point-and-click simplicity. Create connections between objects to define relationships and flow with click-and-drag motion. You’ll be creating your system layout quickly and intuitively.

Standard Object Library

FlexSim includes a whole library of objects that can be used immediately to build many of different models.FlexSim objects are easily customized using pre-configured picklist options to define unique behaviors.

Because no two systems are alike, objects are easily customized by choosing from a list of preconfigured behaviors. A variety of actions are possible – you can even mix and match included options, or create your own.

Get help when you need it

When you’re customizing objects and creating your own behaviors, you’ll appreciate FlexSim’s context sensitive help buttons on every graphical interface, automatic command completion tips, and comprehensive function documentation.

View the difference

FlexSim's views include 2D planar, 3D orthographic and perspective, and hierarchical tree view. Together these views allow you to see your simulation model like never before.View your model in 2D, 3D, or in a hierarchical tree view. Each view gives you a unique perspective on what is going on in your simulation. You can develop your models exclusively using one view, or keep several views open simultaneously for faster model building.

Active Community Forum

FlexSim has an active worldwide community of users
FlexSim users can share tips and tricks, get modeling advice, or ask for help at the FlexSim Community Forum.

Our worldwide user base is active and welcomes simulation newcomers. Users, both new and expert, engage in discussions about all aspects of simulation andFlexSim has an active worldwide community of usersFlexSim Simulation Software. Technical support staff and FlexSim developers frequently give an insider’s view to the discussions.

Visit the Community Forum

Customize your modeling experience

No other simulation software compares to the level of customization that FlexSim provides. You can create your own classes, libraries, GUIs, or applications. FlexSim opens up what most competing products protect as source code.

Shapes & layouts

Add excitement and realism to your model by using custom 3D shapes of your buildings, machines, or products. Import 2D or 3D CAD drawings to use as a floorplan or topographical layout.

Whatever you’re simulating, with FlexSim’s graphics the sky is the limit.

User created objects

FlexSim has a very capable library of class objects that can be used right out of the box to build a variety of different models quickly, with little or no programming required.

Where more complicated or customized behaviors are required, all FlexSim objects can be extended with the use of trigger logic. In addition, the source code for all classes in the library is open to the user to see and use freely. Users can create their own custom objects from scratch, or use existing library objects as a jump-off point.

Custom controls & interfaces

By including custom interfaces in your model, you make using and sharing your model easier. Create GUIs for individual custom objects, or to control your whole model.

Ultimate extensibility

You’ll never have to throw your hands up in frustration because FlexSim can’t do something. FlexSim’s open architecture and integration with the most powerful and widespread programming language available – C++, means that FlexSim can be extended with any functionality imaginable – from sockets and servers to home brewed DLLs.

No programming – no problem

You don’t have to be a C++ programmer to make the most of FlexSim’s flexibility. There’s a simple scripting language available, not to mention all of the pre-configured picklist options that come packaged with FlexSim. Where you meet a brick wall with other simulation software packages, FlexSim gives you a door.

FlexSim Express


Extension Modules

Shaders and Animations


Full Customization

Maximum of 30 Objects

Free Download

FlexSim Enterprise


Extension Modules

Shaders and Animations


Full Customization

Unlimited Objects

Contact FlexSim

System Requirements

FlexSim is designed to run on most modern Windows systems. Unique or complex modeling situations may carry additional hardware requirements.

Check out this FlexSim Answers article for an in-depth discussion regarding the components that make the most difference when building and running your simulation models.

Minimum System Requirements

Most desktop and laptop computers produced in the last few years meet FlexSim’s minimum specs. A system that meets these specs will allow you to evaluate FlexSim, go through the tutorials, and build small to medium sized models.

Recommended Specs

For the best experience—and for larger, more graphically intense, or complex models, including importing custom shapes and using the experimenter or optimizer features—we recommend upgrading the minimum specs to at least the following:

CPUAny modern1 x86 or x64 Intel or AMD processorCPU A CPU scoring 12,000 or better in PassMark – CPU Mark benchmark, such as:

GraphicsAny GPU that supports OpenGL 3.1 or higher:

  • Nvidia GeForce 300 Series or higher
  • AMD Radeon R600 (HD 2xxx, HD 3xxx) Series or higher
  • Intel HD 2000 or higher
Graphics A GPU scoring 8,000 or better in PassMark – G3d Mark benchmark, such as:

OSAny Microsoft-supported Windows operating system2, 32- or 64-bit.
Currently supported editions of Windows include:

OSOne of the latest two releases of Microsoft Windows 10, 64-bit.
Disk2.5 GB free

  • FlexSim’s installer may be up to 1.2 GB in size, depending on version. After successful installation, the installer file may be deleted.
  • After installation, FlexSim’s program files will use up to 1.2 GB of disk space.
  • Your model files, CAD layouts, images, custom 3D shapes, import data, exported reports, and other simulation related assets that you provide will take disk space in addition to the software’s installation footprint.
Additional Software
  1. Some modern low power processors, such as Intel’s Atom, have lower performance in highly demanding apps like FlexSim than mainstream desktop and notebook processors. Consequently, large simulations will take longer to complete on these low power CPUs. ARM processors are not supported.
  2. Once an operating system reaches its end of extended support with Microsoft, FlexSim no longer actively supports that OS. Windows on ARM is not supported.
  3. FlexSim uses functionality provided by Microsoft’s latest .NET framework. The .NET framework is already installed on most computers. It can be freely obtained from Microsoft Windows Update, or as a standalone download directly from Microsoft. In addition, FlexSim’s OptQuest add-on requires .NET framework version 3.5.
  4. Microsoft’s Visual Studio can be used in conjunction with FlexSim to build compiled models or enhance system level functionality (OS, network, etc.). These features are optional, however. FlexSim does not require a compiler to build or run simulation models. Microsoft’s Visual Studio Community is a free download from Microsoft Corporation.