Best Simulation Software: 11 Options for Modelling Systems

A simulation lets you break your process on screen instead of on the shop floor. Add a machine, remove a shift, double the orders, and you can watch where the queue forms before anyone moves a single pallet.

The eleven tools below are listed alphabetically and in no particular order, from free browser-based modellers to suites built for whole factories. Every description comes from the vendor's own site, read this week. If you're looking at the wider picture, my piece on how better tools are reshaping manufacturing efficiency is a useful companion.

Simulation software at a glance

In the free plan column, Yes means the tool's own site names a free plan, a free version, a free app or an open source edition. Trial only means a time-limited trial. Not stated means the pages I read named neither, even where there's a button inviting you to try it.

Tool	Type	Good for	Free plan
AnyLogic	Simulation modelling, online or desktop	Switching between browser and desktop	Not stated
Arena	Discrete event simulation software	What-if experiments on business systems	Not stated
ExtendSim	Discrete event and continuous process simulation	Continuous process modelling	Not stated
FlexSim	3D simulation modelling and analysis	3D models of factories and warehouses	Trial only
Insight Maker	Free browser-based modelling tool	System dynamics and agent based models	Yes
OpenModelica	Open source Modelica environment	Open source physical system modelling	Yes
Simio	Discrete event simulation and digital twins	Process digital twins with live data	Trial only
Simul8	Simulation software for process improvement	Drag-and-drop process models	Not stated
Simulink	Block diagram simulation and Model-Based Design	Multidomain engineering systems	Not stated
Tecnomatix Plant Simulation	Production and logistics simulation	Plant layouts and material flow	Not stated
Vensim	System dynamics simulation software	Causal loops to tested models	Not stated

Eleven simulation tools to consider

AnyLogic

Best for: Analysts and engineers who want to build simulation models in the browser and switch to the desktop version whenever they need to.

Arena

Best for: Operations teams that want to create and run experiments on models of their systems without disrupting the business itself.

ExtendSim

Best for: Engineers modelling continuous processes as well as discrete events, using a graphical, block-based modelling environment.

FlexSim

Best for: Manufacturing, warehousing and healthcare teams that want a 3D model of a system to test what-if scenarios before changing anything.

Insight Maker

Best for: Students, teachers and curious analysts who want to build system dynamics and agent based models in a browser at no charge.

OpenModelica

Best for: Engineers and researchers who want an open source, Modelica-based modelling and simulation environment for industrial or academic work.

Simio

Best for: Operations leaders who want process digital twins that connect to live data, built on discrete event simulation technology.

Simul8

Best for: Process improvement teams in healthcare, manufacturing and call centres that want quick drag-and-drop models, now part of Minitab.

Simulink

Best for: Engineering teams designing multidomain systems that want to simulate before building hardware and generate code straight from their models.

Tecnomatix Plant Simulation

Best for: Production engineers who want to model, simulate and analyse logistics and material flow, from whole factories down to single lines.

Vensim

Best for: Modellers who want to move from causal loop diagrams to tested system dynamics models, with versions for students and professionals.

Discrete event, system dynamics or physical models?

Most simulation tools lean toward one of three styles. Discrete event tools model things that queue and move, like patients, parts, calls and trucks. System dynamics tools model stocks and flows over months or years, such as staff levels or customer numbers. Engineering tools model physical systems, from motors to hydraulics, and often connect to code.

Pick the style first. A hospital trying to cut waiting times and an engineer designing a gearbox both need simulation, but they don't need the same software.

Decide what would make the model trustworthy

NASA takes this seriously. Its standard NASA-STD-7009 sets uniform practices in modeling and simulation so essential requirements are applied to their design, development and use, with acceptance criteria defined by the project.

You don't need a space programme to borrow the idea. Before anyone builds a model, agree what data it'll use, how you'll check it against reality and what result would change a decision. That conversation saves more time than any feature.

Questions to put to every vendor

1. Which modelling style is the tool built around, and can it mix styles?
2. How does it import real data from spreadsheets, databases or our ERP?
3. Can non-specialists run experiments on a finished model?
4. How are results shown: 3D animation, charts, reports or all three?
5. Is there an academic or learning edition for training staff?
6. Can models be shared online or only on the desktop?

Features that save time later

• Data import. Real inputs beat typed guesses every time.
• Experiment runner. You can test dozens of scenarios in one go.
• Clear visuals. Managers trust what they can see moving.
• Model sharing. Colleagues can run scenarios without a licence of their own.

Signs a spreadsheet model has run its course

If your planning sheet needs a new tab every time someone asks what if, or the numbers never match what happens on a busy day, it's time for a simulation. Variability is the thing spreadsheets hide best.

Do you make simulation software? Tool makers can ask to be considered for a featured place on this list.

My plain advice on choosing simulation software

Start with one real question you need answered, such as how many staff a busy Saturday needs or where a new machine should go. Build a small model in two or three tools that suit your style, and see which one gets you to a believable answer fastest.

Then think about who'll use the model after you. If managers will want to play with scenarios, favour a tool that makes running experiments simple. If you'd like a gentle way into operations thinking, Scale-up, a business game about running operations is a fun place to start.

Frequently asked questions

What is simulation software?

It's software that builds a digital model of a system, such as a factory, clinic or supply chain, so you can test changes and see their effect before making them for real.

Is there free simulation software?

Yes. Insight Maker describes itself as completely free and OpenModelica is open source. Check the table for each tool's free plan status.

What is discrete event simulation?

It models a system as a series of events, such as a part arriving or a patient being seen, which makes it good for queues, workflows and logistics.

What's the difference between simulation and a spreadsheet?

A spreadsheet usually works with averages. A simulation accounts for time, variability and how parts of a system affect each other, which is where averages tend to mislead.

Do I need to code to use simulation software?

Not always. Several tools here use drag-and-drop or block diagrams, while others let you add code when a model needs more detail.

How do I know a simulation model is accurate?

Compare its results with real data from the system you're modelling, and agree before you start what level of accuracy you need to make a decision.