What differentiates ExtendSim from other simulation tools?

We are often asked, "what sets ExtendSim apart from other simulation software products?" There are a multitude of distinguishing features, but here is the short list of what sets ExtendSim apart:

Interactive - Make Changes on the Fly

Even during a model run, ExtendSim parameters and model logic can be changed "on the fly" rather than having to wait until the simulation ends. This means you can get fully involved with an ExtendSim model, even play with it, and leave no alternative unexplored. ExtendSim's point and click interactivity translates into faster answers and winning solutions.

There is no code generation phase.

You can change inputs and view model results while the mode runs.

Equations can be tested without running the model

Reusable - Hierarchy

You can create, reuse, even distribute ExtendSim blocks - the components that comprise a model. Group existing blocks to save them as one hierarchical block. Or develop custom blocks with unique behaviors, icons, and dialogs. Store your new block in an ExtendSim library for reuse in other models or for distribution to others. ExtendSim's hierarchy allows for unique identities for each block and permits block information to be used locally.

Block reusability increases productivity, improves consistency of design, and avoids having to reinvent the wheel each time you build a new model.

Customizable - Cloning

Create live interfaces. Clone significant parameters and/or results by dragging and dropping them to a centralized location so you can easily change parameters and immediately view the results. Place clones on the model worksheet or use ExtendSim's Notebook feature to create a virtual dashboard so you are in direct control of your model. In addition to parameters and results, you can clone buttons, sliders, plotters, and more.

Scalable - Expert Large Scale Modeling Tool, yet Practical for Smaller Models

Because of its powerful constructs, unlimited hierarchical structure, and internal database, ExtendSim is the simulation tool of choice for producing complex, accurate enterprise-wide models (we've seen models containing a million items and more than 300,000 blocks!), while remaining practical enough to build small to mid scale models.

Plus, ExtendSim gives you the option to add more flexibility with add-ons from Expert Solution Providers. With ExtendSim, you always have full capability to model any size project.

Visually Transparent

Block icons convey the structure and behavior of the model at a glance. In ExtendSim, both the flow of items and the flow of values are graphically represented. This unique mapping of visual meanings into their equivalent icons promotes quick understanding of a model to anyone viewing it. Plus, makes model construction and validation easier.

Superior Data Handling

ExtendSim adeptly manages very large data sets.

Integrated relational database to centralize and organize model data.

Multiple methods for data import/export.

Link databases with dialogs.

Link-alerts notify appropriate blocks when data changes.

Well Connected - Dynamic Data Linkage

In addition to its integrated relational database, ExtendSim communicates seamlessly with the most commonly used external databases. ActiveX Data Objects (ADO) provides built-in import and export support for Microsoft Access, SQL Server, and MySQL.

Plus, ExtendSim supports COM/ActiveX and ODBC/SQL. Dynamically link data to an ExtendSim database, embed an Excel spreadsheet in a model, control an external application, or have the other application control ExtendSim.

These technologies have been implemented as modeling components so that communication within ExtendSim and between applications are click-and-drop operations, with no programming necessary. It's a powerful, easy-to-use, and fast interface to popular software such as Excel, Minitab, and JMP.

Extendable (open source) - Even Greater Control

ExtendSim block components are developed using its compiled language and integrated development environment. They are Open Source to allow modification and enhancement. You can alter existing blocks and develop new proprietary components for distribution to internal or external customers. Linking to code and routines written in external languages is also supported. ExtendSim's open source architecture gives you the freedom to model anything.

You have greater control with ExtendSim. If you want to, you can even access and change ExtendSim's event scheduling procedures as you are granted full access to discrete event algorithms and data structures.

Most users never find the need to use this feature, but it's available if you need it.

Rate-Based Modeling

Rate-based modeling is based on rates of flow (material, product, data, etc.) that change when events occur. Systems where there are no specific items that can be identified or when there are so many items that identification is meaningless, can be more naturally represented using a rate-based approach rather than discrete event modeling. Rate-based models run faster than discrete event models and are applicable to thinking in terms of flows, tanks, rates, and so forth. Until recently, rate-based systems could not be efficiently represented in software tools.

...at least until Imagine That Inc. dreamed up the idea to use LP technology to provide global oversight for calculations in mixed discrete event/discrete rate models. With the ExtendSim Rate library (included in the ExtendSim AT package), you can expect errorless modeling of your rate-based systems. It's even more robust for linear continuous systems.

Global Reach

ExtendSim is so flexible it has become the simulation engine used by most OEM developers and the learning tool used by most educators. This expands ExtendSim's reach around the globe. That's why you will find ExtendSim being used in so many different industries, written up in a multitude of publications, and included with numerous textbooks.


ExtendSim maximizes modeler productivity. It is an interactive, reusable, and visual tool that accelerates model building and enhances your understanding of complex systems.

Experience the advantages ExtendSim users realize every day and solve your unusual, complex problems elegantly.