An @RISK alternative that opens your @RISK workbooks
VionRisk is a Monte Carlo simulation add-in for Microsoft Excel that runs @RISK workbooks unchanged: it reads @RISK's worksheet functions (RiskNormal, RiskPert, RiskOutput, RiskCorrmat and the rest), lets Excel calculate the model, and lets AI agents explain the results.
This page sets out, as fairly as we can, what VionRisk does compatibly with @RISK, how we test it, and what @RISK has that VionRisk does not yet. @RISK, originally from Palisade, is now sold by Lumivero.
Who VionRisk is for
- Teams with existing @RISK models who want a second engine to check results, or more seats, without rebuilding their workbooks.
- Analysts who want AI agents to read their simulations and explain the drivers, with the numbers behind every claim.
- Regulated teams who need every result to record the software and environment that produced it, and the maths and assumptions written down.
What runs compatibly
VionRisk reads 239 @RISK worksheet functions:
- 46 continuous and 10 discrete distributions, plus 48 percentile-based Alt and AltD forms and 5 special ones (RiskCompound, RiskSplice, RiskMakeInput ...)
- 22 property functions: RiskTruncate, RiskShift, RiskName, RiskCorrmat, RiskCopula, RiskDepC / RiskIndepC, RiskSeed, RiskLock and more
- Statistics: 33 simulation statistics, 18 theoretical (RiskTheo*) and 19 Six Sigma functions
- 17 time series functions (13 processes and 4 properties), 8 fitting functions, 4 what-if functions (RiskSimTable, RiskVary ...) and RiskOutput
Workbooks saved with @RISK's Swap-Out option are read too. Excel calculates every formula, as it does under @RISK, and VionRisk runs on a hidden copy, so your workbook is never modified.
How we test compatibility
A conformance workbook puts every function in a cell with its theoretical statistics. We run it in a licensed copy of @RISK and in VionRisk and compare the values.
The other 11 differ only where VionRisk keeps the exact mathematical value and @RISK's is an approximation - for example the kurtosis of RiskFatigueLife, the moments of a truncated RiskPoisson or RiskCompound - and each one is documented with the working. The run that got here also fixed real differences in VionRisk (the minimum and percentiles of some discrete distributions, RiskSplice, the theoretical mode); those fixes are merged for the next release, 0.7.1. Ask us for the report.
VionRisk 0.7.0 at a glance
"Available" means in the add-in today. "Next release" means in development for 0.7.1. "Planned" means agreed on the roadmap, without a date.
| Capability | In VionRisk | Status |
|---|---|---|
| Open and simulate @RISK workbooks | Risk* functions read as they are; Swap-Out workbooks too | Available |
| Distributions | 106, with Alt forms, truncation, shift, empirical and spliced distributions | Available |
| Sampling | Latin Hypercube or Monte Carlo, fixed seed, iterations and simulations you set | Available |
| Correlation | Correlation matrices, DepC / IndepC; Gaussian, t, Clayton, Gumbel and Frank copulas | Available |
| Fit distributions to data | Maximum likelihood; ranked by AIC, BIC, chi-square, K-S, A-D; P-P and Q-Q plots | Available |
| Time series | 13 processes (AR to GARCH, GBM with jumps, mean reversion) with fan charts | Available |
| Sensitivity | Tornado (change in mean, regression, rank correlation, contribution to variance), spider, scenarios | Available |
| Multiple simulations and what-if | RiskSimTable, Vary tables, what-ifs on a copy | Available |
| Reports | Summary, Quick, input, output, detailed statistics, sensitivity, scenario, data; PDF, HTML, Excel | Available |
| AI agents | MCP server with 18 tools; Ask VionRisk in the ribbon; AI Pack export | Available |
| Audit trail of each result | VionRisk, Excel, Python and package versions and the OS stamped on every output | Available |
| Multiple CPUs | Iterations spread across processor cores, results identical to one CPU | Next release |
| Advanced analyses | Goal Seek, Stress Analysis, Advanced Sensitivity Analysis | Next release |
| Summary graphs | Box plots, trend and letter-value summary graphs; scenario graphs | Planned |
| Optimisation | An optimiser in the spirit of RISKOptimizer | Being studied |
| Project schedules | Schedule risk analysis on imported project plans (today: schedules modelled in Excel) | Being studied |
| Excel for the web, teams | VionRisk in the browser and shared results | Planned |
What @RISK has that VionRisk does not yet
- RISKOptimizer, for optimisation under uncertainty
- Schedule risk analysis on project plans
- Goal Seek, Stress Analysis and Advanced Sensitivity Analysis (coming in VionRisk's next release)
- Multiple CPU simulation (next release)
- Some summary and scenario graphs, such as box plots
- The maturity of a product with a long history: an installed base, training courses, consultants and a support organisation
- Companion tools in the same suite
What VionRisk adds
- AI agents that read your simulations and explain them, through an open standard (MCP), with the AI app you choose or a private endpoint
- VR* function names, so VionRisk and @RISK can be loaded together to compare
- The assumptions check: observed data tested against a model's assumptions (OK, Watch, Breach)
- Exact maths, with every convention and assumption written down
- The software and environment stamped on every result
- A team that builds it and answers you directly during a pilot
Crystal Ball models
Oracle Crystal Ball is another established Monte Carlo add-in for Excel. It defines most assumptions through its own dialogs rather than worksheet formulas, so Crystal Ball models do not open in VionRisk as they are. They can be rebuilt with VionRisk's distribution functions, which then work like any @RISK-style model: in cells, visible, and easy to review. In a pilot we can rebuild one of your models with you and compare the results.
Other alternatives
Teams looking for an @RISK alternative also consider Oracle Crystal Ball, Analytic Solver / Risk Solver from Frontline Systems, ModelRisk from Vose Software and RiskAMP, or move models to Python or R. Each has its own model format; VionRisk is the one built to run @RISK workbooks as they are. The best test is your own models: run them side by side and compare.
@RISK alternative: questions
What are the alternatives to Palisade @RISK for Monte Carlo simulation in Excel?
Established Excel add-ins include Oracle Crystal Ball, Analytic Solver / Risk Solver from Frontline Systems, ModelRisk from Vose Software and RiskAMP; some teams use Python or R instead. VionRisk is the alternative that opens @RISK workbooks as they are: it reads @RISK's worksheet functions, so existing models run without being rebuilt, and AI agents can explain the results.
Does VionRisk run my @RISK workbooks without changes?
Yes. VionRisk reads @RISK's Risk* worksheet functions - 239 functions, including all distribution, property, statistic, fitting and time series functions - and simulates the workbook with Excel calculating every formula. It also reads workbooks saved with @RISK's Swap-Out option. Your file is never modified.
Do VionRisk and @RISK give the same results?
They use the same definitions, and VionRisk is tested against a licensed copy of @RISK with a conformance workbook that covers every function. In the latest run all 121 functions compared agree: 110 exactly, and 11 where VionRisk keeps the exact mathematical value and @RISK's is an approximation, each one documented. Simulated values differ from run to run in any tool unless the random streams are identical, so compare statistics, not single iterations.
What does @RISK have that VionRisk does not yet?
RISKOptimizer (optimisation under uncertainty), @RISK's project schedule risk tools, Goal Seek, Stress Analysis and Advanced Sensitivity Analysis (in VionRisk's next release), multiple CPU simulation (next release), scenario and summary graphs such as box plots (planned), and the maturity, training and support organisation of a product with a long history.
Can VionRisk and @RISK be installed side by side?
Yes. VionRisk's own functions are named VR* (VRPert, VRNormal, VROutput) so they do not clash with @RISK's Risk* functions, and both add-ins can be loaded at once to compare results. Utilities > Convert switches a workbook between the two sets of names.
Does VionRisk open Oracle Crystal Ball models?
Not directly. Crystal Ball defines most assumptions through its own dialogs rather than worksheet formulas, so its models do not open in VionRisk as they are. They can be rebuilt with VionRisk's distribution functions; we can do that with you for a model in a pilot.
Run your @RISK models in VionRisk
A 60-day pilot on your own computers, with your workbooks checked side by side with your current tool.